Use typing_extensions.Self instead of _typeshed.Self (#9702)

stubs/PyMySQL/pymysql/connections.pyi

@@ -1,7 +1,8 @@
-from _typeshed import Incomplete, Self
+from _typeshed import Incomplete
 from collections.abc import Mapping
 from socket import socket as _socket
 from typing import Any, AnyStr, Generic, TypeVar, overload
+from typing_extensions import Self
 
 from .charset import charset_by_id as charset_by_id, charset_by_name as charset_by_name
 from .constants import CLIENT as CLIENT, COMMAND as COMMAND, FIELD_TYPE as FIELD_TYPE, SERVER_STATUS as SERVER_STATUS
@@ -197,7 +198,7 @@ class Connection(Generic[_C]):
     def get_proto_info(self): ...
     def get_server_info(self): ...
     def show_warnings(self): ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *exc_info: object) -> None: ...
     Warning: Any
     Error: Any

stubs/PyMySQL/pymysql/cursors.pyi

@@ -1,6 +1,6 @@
-from _typeshed import Self
 from collections.abc import Iterable, Iterator
 from typing import Any
+from typing_extensions import Self
 
 from .connections import Connection
 
@@ -24,7 +24,7 @@ class Cursor:
     def executemany(self, query: str, args: Iterable[object]) -> int | None: ...
     def callproc(self, procname: str, args: Iterable[Any] = ...) -> Any: ...
     def scroll(self, value: int, mode: str = ...) -> None: ...
-    def __enter__(self: Self) -> Self: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *exc_info: object) -> None: ...
     # Methods returning result tuples are below.
     def fetchone(self) -> tuple[Any, ...] | None: ...