convert uses of interface{} to any

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

PiperOrigin-RevId: 487033228

pkg/sentry/hostfd/hostfd.go

@@ -32,7 +32,7 @@ type ReadWriterAt struct {
 }
 
 var rwpool = sync.Pool{
-	New: func() interface{} {
+	New: func() any {
 		return &ReadWriterAt{}
 	},
 }