Remove redundant copyBufferPool from relay

mtglib/internal/relay/pools.go

-package relay
-
-import "sync"
-
-var copyBufferPool = sync.Pool{
-	New: func() any {
-		rv := make([]byte, copyBufferSize)
-
-		return &rv
-	},
-}
-
-func acquireCopyBuffer() *[]byte {
-	return copyBufferPool.Get().(*[]byte) //nolint: forcetypeassert
-}
-
-func releaseCopyBuffer(buf *[]byte) {
-	copyBufferPool.Put(buf)
-}

mtglib/internal/relay/relay.go

 }
 
 func pump(log Logger, src, dst essentials.Conn, direction string) {
+	var buf [copyBufferSize]byte
+
 	defer src.CloseRead()  //nolint: errcheck
 	defer dst.CloseWrite() //nolint: errcheck
 
-	copyBuffer := acquireCopyBuffer()
-	defer releaseCopyBuffer(copyBuffer)
-
-	n, err := io.CopyBuffer(src, dst, *copyBuffer)
+	n, err := io.CopyBuffer(src, dst, buf[:])
 
 	switch {
 	case err == nil: