[socket] Use concrete classes for socket.makefile return types (#16587)

Author: srittau

stdlib/socket.pyi

@@ -136,7 +136,7 @@ from _socket import (
 from _typeshed import ReadableBuffer, Unused, WriteableBuffer
 from collections.abc import Iterable
 from enum import IntEnum, IntFlag
-from io import BufferedReader, BufferedRWPair, BufferedWriter, IOBase, RawIOBase, TextIOWrapper
+from io import BufferedReader, BufferedRWPair, BufferedWriter, RawIOBase, TextIOWrapper
 from typing import Any, Final, Literal, Protocol, SupportsIndex, TypeAlias, overload, type_check_only
 from typing_extensions import Self
 
@@ -1507,7 +1507,7 @@ class socket(_socket.socket):
         encoding: str | None = None,
         errors: str | None = None,
         newline: str | None = None,
-    ) -> IOBase: ...
+    ) -> SocketIO | BufferedRWPair | BufferedReader | BufferedWriter: ...
     @overload
     def makefile(
         self,