Update dependencies

vendor/tailscale.com/syncs/shardvalue_go.go

@@ -0,0 +1,36 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+//go:build !tailscale_go
+
+package syncs
+
+import (
+	"runtime"
+	"sync"
+	"sync/atomic"
+)
+
+type shardValuePool struct {
+	atomic.Int64
+	sync.Pool
+}
+
+// NewShardValue constructs a new ShardValue[T] with a shard per CPU.
+func NewShardValue[T any]() *ShardValue[T] {
+	sp := &ShardValue[T]{
+		shards: make([]T, runtime.NumCPU()),
+	}
+	sp.pool.New = func() any {
+		i := sp.pool.Add(1) - 1
+		return &sp.shards[i%int64(len(sp.shards))]
+	}
+	return sp
+}
+
+// One yields a pointer to a single shard value with best-effort P-locality.
+func (sp *ShardValue[T]) One(yield func(*T)) {
+	v := sp.pool.Get().(*T)
+	yield(v)
+	sp.pool.Put(v)
+}