Use PEP 570 syntax in stdlib (#11250)

stdlib/socket.pyi

@@ -682,8 +682,8 @@ if sys.platform == "win32":
     errorTab: dict[int, str]  # undocumented
 
 class _SendableFile(Protocol):
-    def read(self, __size: int) -> bytes: ...
-    def seek(self, __offset: int) -> object: ...
+    def read(self, size: int, /) -> bytes: ...
+    def seek(self, offset: int, /) -> object: ...
 
     # optional fields:
     #