Add vendor directory and update vendorHash to null

vendor/golang.org/x/sync/LICENSE

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+Copyright 2009 The Go Authors.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google LLC nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/golang.org/x/sync/PATENTS

@@ -0,0 +1,22 @@
+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.

vendor/golang.org/x/sync/errgroup/errgroup.go

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+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package errgroup provides synchronization, error propagation, and Context
+// cancelation for groups of goroutines working on subtasks of a common task.
+//
+// [errgroup.Group] is related to [sync.WaitGroup] but adds handling of tasks
+// returning errors.
+package errgroup
+
+import (
+	"context"
+	"fmt"
+	"sync"
+)
+
+type token struct{}
+
+// A Group is a collection of goroutines working on subtasks that are part of
+// the same overall task. A Group should not be reused for different tasks.
+//
+// A zero Group is valid, has no limit on the number of active goroutines,
+// and does not cancel on error.
+type Group struct {
+	cancel func(error)
+
+	wg sync.WaitGroup
+
+	sem chan token
+
+	errOnce sync.Once
+	err     error
+}
+
+func (g *Group) done() {
+	if g.sem != nil {
+		<-g.sem
+	}
+	g.wg.Done()
+}
+
+// WithContext returns a new Group and an associated Context derived from ctx.
+//
+// The derived Context is canceled the first time a function passed to Go
+// returns a non-nil error or the first time Wait returns, whichever occurs
+// first.
+func WithContext(ctx context.Context) (*Group, context.Context) {
+	ctx, cancel := context.WithCancelCause(ctx)
+	return &Group{cancel: cancel}, ctx
+}
+
+// Wait blocks until all function calls from the Go method have returned, then
+// returns the first non-nil error (if any) from them.
+func (g *Group) Wait() error {
+	g.wg.Wait()
+	if g.cancel != nil {
+		g.cancel(g.err)
+	}
+	return g.err
+}
+
+// Go calls the given function in a new goroutine.
+//
+// The first call to Go must happen before a Wait.
+// It blocks until the new goroutine can be added without the number of
+// goroutines in the group exceeding the configured limit.
+//
+// The first goroutine in the group that returns a non-nil error will
+// cancel the associated Context, if any. The error will be returned
+// by Wait.
+func (g *Group) Go(f func() error) {
+	if g.sem != nil {
+		g.sem <- token{}
+	}
+
+	g.wg.Add(1)
+	go func() {
+		defer g.done()
+
+		// It is tempting to propagate panics from f()
+		// up to the goroutine that calls Wait, but
+		// it creates more problems than it solves:
+		// - it delays panics arbitrarily,
+		//   making bugs harder to detect;
+		// - it turns f's panic stack into a mere value,
+		//   hiding it from crash-monitoring tools;
+		// - it risks deadlocks that hide the panic entirely,
+		//   if f's panic leaves the program in a state
+		//   that prevents the Wait call from being reached.
+		// See #53757, #74275, #74304, #74306.
+
+		if err := f(); err != nil {
+			g.errOnce.Do(func() {
+				g.err = err
+				if g.cancel != nil {
+					g.cancel(g.err)
+				}
+			})
+		}
+	}()
+}
+
+// TryGo calls the given function in a new goroutine only if the number of
+// active goroutines in the group is currently below the configured limit.
+//
+// The return value reports whether the goroutine was started.
+func (g *Group) TryGo(f func() error) bool {
+	if g.sem != nil {
+		select {
+		case g.sem <- token{}:
+			// Note: this allows barging iff channels in general allow barging.
+		default:
+			return false
+		}
+	}
+
+	g.wg.Add(1)
+	go func() {
+		defer g.done()
+
+		if err := f(); err != nil {
+			g.errOnce.Do(func() {
+				g.err = err
+				if g.cancel != nil {
+					g.cancel(g.err)
+				}
+			})
+		}
+	}()
+	return true
+}
+
+// SetLimit limits the number of active goroutines in this group to at most n.
+// A negative value indicates no limit.
+// A limit of zero will prevent any new goroutines from being added.
+//
+// Any subsequent call to the Go method will block until it can add an active
+// goroutine without exceeding the configured limit.
+//
+// The limit must not be modified while any goroutines in the group are active.
+func (g *Group) SetLimit(n int) {
+	if n < 0 {
+		g.sem = nil
+		return
+	}
+	if len(g.sem) != 0 {
+		panic(fmt.Errorf("errgroup: modify limit while %v goroutines in the group are still active", len(g.sem)))
+	}
+	g.sem = make(chan token, n)
+}

vendor/golang.org/x/sync/semaphore/semaphore.go

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+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package semaphore provides a weighted semaphore implementation.
+package semaphore // import "golang.org/x/sync/semaphore"
+
+import (
+	"container/list"
+	"context"
+	"sync"
+)
+
+type waiter struct {
+	n     int64
+	ready chan<- struct{} // Closed when semaphore acquired.
+}
+
+// NewWeighted creates a new weighted semaphore with the given
+// maximum combined weight for concurrent access.
+func NewWeighted(n int64) *Weighted {
+	w := &Weighted{size: n}
+	return w
+}
+
+// Weighted provides a way to bound concurrent access to a resource.
+// The callers can request access with a given weight.
+type Weighted struct {
+	size    int64
+	cur     int64
+	mu      sync.Mutex
+	waiters list.List
+}
+
+// Acquire acquires the semaphore with a weight of n, blocking until resources
+// are available or ctx is done. On success, returns nil. On failure, returns
+// ctx.Err() and leaves the semaphore unchanged.
+func (s *Weighted) Acquire(ctx context.Context, n int64) error {
+	done := ctx.Done()
+
+	s.mu.Lock()
+	select {
+	case <-done:
+		// ctx becoming done has "happened before" acquiring the semaphore,
+		// whether it became done before the call began or while we were
+		// waiting for the mutex. We prefer to fail even if we could acquire
+		// the mutex without blocking.
+		s.mu.Unlock()
+		return ctx.Err()
+	default:
+	}
+	if s.size-s.cur >= n && s.waiters.Len() == 0 {
+		// Since we hold s.mu and haven't synchronized since checking done, if
+		// ctx becomes done before we return here, it becoming done must have
+		// "happened concurrently" with this call - it cannot "happen before"
+		// we return in this branch. So, we're ok to always acquire here.
+		s.cur += n
+		s.mu.Unlock()
+		return nil
+	}
+
+	if n > s.size {
+		// Don't make other Acquire calls block on one that's doomed to fail.
+		s.mu.Unlock()
+		<-done
+		return ctx.Err()
+	}
+
+	ready := make(chan struct{})
+	w := waiter{n: n, ready: ready}
+	elem := s.waiters.PushBack(w)
+	s.mu.Unlock()
+
+	select {
+	case <-done:
+		s.mu.Lock()
+		select {
+		case <-ready:
+			// Acquired the semaphore after we were canceled.
+			// Pretend we didn't and put the tokens back.
+			s.cur -= n
+			s.notifyWaiters()
+		default:
+			isFront := s.waiters.Front() == elem
+			s.waiters.Remove(elem)
+			// If we're at the front and there're extra tokens left, notify other waiters.
+			if isFront && s.size > s.cur {
+				s.notifyWaiters()
+			}
+		}
+		s.mu.Unlock()
+		return ctx.Err()
+
+	case <-ready:
+		// Acquired the semaphore. Check that ctx isn't already done.
+		// We check the done channel instead of calling ctx.Err because we
+		// already have the channel, and ctx.Err is O(n) with the nesting
+		// depth of ctx.
+		select {
+		case <-done:
+			s.Release(n)
+			return ctx.Err()
+		default:
+		}
+		return nil
+	}
+}
+
+// TryAcquire acquires the semaphore with a weight of n without blocking.
+// On success, returns true. On failure, returns false and leaves the semaphore unchanged.
+func (s *Weighted) TryAcquire(n int64) bool {
+	s.mu.Lock()
+	success := s.size-s.cur >= n && s.waiters.Len() == 0
+	if success {
+		s.cur += n
+	}
+	s.mu.Unlock()
+	return success
+}
+
+// Release releases the semaphore with a weight of n.
+func (s *Weighted) Release(n int64) {
+	s.mu.Lock()
+	s.cur -= n
+	if s.cur < 0 {
+		s.mu.Unlock()
+		panic("semaphore: released more than held")
+	}
+	s.notifyWaiters()
+	s.mu.Unlock()
+}
+
+func (s *Weighted) notifyWaiters() {
+	for {
+		next := s.waiters.Front()
+		if next == nil {
+			break // No more waiters blocked.
+		}
+
+		w := next.Value.(waiter)
+		if s.size-s.cur < w.n {
+			// Not enough tokens for the next waiter.  We could keep going (to try to
+			// find a waiter with a smaller request), but under load that could cause
+			// starvation for large requests; instead, we leave all remaining waiters
+			// blocked.
+			//
+			// Consider a semaphore used as a read-write lock, with N tokens, N
+			// readers, and one writer.  Each reader can Acquire(1) to obtain a read
+			// lock.  The writer can Acquire(N) to obtain a write lock, excluding all
+			// of the readers.  If we allow the readers to jump ahead in the queue,
+			// the writer will starve — there is always one token available for every
+			// reader.
+			break
+		}
+
+		s.cur += w.n
+		s.waiters.Remove(next)
+		close(w.ready)
+	}
+}