chore: declare the return type of the ReadableStreamInterface::pipe() method via @template.

Author: 7-zete-7

src/ReadableStreamInterface.php

@@ -318,9 +318,10 @@ public function resume(): void;
      * Once the pipe is set up successfully, the destination stream MUST emit
      * a `pipe` event with this source stream an event argument.
      *
-     * @param WritableStreamInterface $dest
+     * @template T of WritableStreamInterface
+     * @param T $dest
      * @param array{end?:bool} $options
-     * @return WritableStreamInterface $dest stream as-is
+     * @return T $dest stream as-is
      */
     public function pipe(WritableStreamInterface $dest, array $options = []): WritableStreamInterface;