asyncore: improve bytes handling (#9034)

Author: sobolevn

stdlib/asyncore.pyi

@@ -1,5 +1,5 @@
 import sys
-from _typeshed import FileDescriptorLike
+from _typeshed import FileDescriptorLike, ReadableBuffer
 from socket import socket
 from typing import Any, overload
 from typing_extensions import TypeAlias
@@ -45,7 +45,7 @@ class dispatcher:
     def bind(self, addr: tuple[Any, ...] | str) -> None: ...
     def connect(self, address: tuple[Any, ...] | str) -> None: ...
     def accept(self) -> tuple[_Socket, Any] | None: ...
-    def send(self, data: bytes) -> int: ...
+    def send(self, data: ReadableBuffer) -> int: ...
     def recv(self, buffer_size: int) -> bytes: ...
     def close(self) -> None: ...
     def log(self, message: Any) -> None: ...