convert uses of interface{} to any

Done via:
  find . -name "*.go" | xargs sed -i -E 's/interface\{\}/any/g'

PiperOrigin-RevId: 487033228

pkg/syncevent/waiter_test.go

@@ -190,7 +190,7 @@ func BenchmarkSleeperMultiNotifyWaitAck(b *testing.B) {
 	// The sleep package doesn't provide sync.Pool allocation of Wakers;
 	// we do for a fairer comparison.
 	wakerPool := sync.Pool{
-		New: func() interface{} {
+		New: func() any {
 			return &sleep.Waker{}
 		},
 	}
@@ -229,7 +229,7 @@ func BenchmarkSleeperTempNotifyWaitAck(b *testing.B) {
 	// The sleep package doesn't provide sync.Pool allocation of Sleepers;
 	// we do for a fairer comparison.
 	sleeperPool := sync.Pool{
-		New: func() interface{} {
+		New: func() any {
 			return &sleep.Sleeper{}
 		},
 	}

pkg/syncevent/waiter_unsafe.go

@@ -174,7 +174,7 @@ func (w *Waiter) NotifyPending() {
 }
 
 var waiterPool = sync.Pool{
-	New: func() interface{} {
+	New: func() any {
 		w := &Waiter{}
 		w.Init()
 		return w