Always use _typeshed.Self, where applicable (#6880)

* Always use `_typeshed.Self`, where applicable

* Revert changes to `google-cloud-ndb` (ambiguous)

* Remove empty line added by script

* Revert changes to `stubs/python-dateutil/dateutil/relativedelta.pyi`

* Manually add a few more that the script missed

* Improve `filelock` annotation

Source code here: https://github.com/tox-dev/py-filelock/blob/79ec7b2826e33b982fe83b057f359448b9d966ba/src/filelock/_api.py#L207

* Improve `opentracing/scope` annotation

Source code here: https://github.com/opentracing/opentracing-python/blob/3e1d357a348269ef54d67f761302fab93dbfc0f7/opentracing/scope.py#L71

* Improve `redis/client` stub

Source code here: https://github.com/redis/redis-py/blob/15f315a496c3267c8cbcc6d6d9c6005ea4d4a4d5/redis/client.py#L1217

* Improve `redis/lock` annotation

Source code here: https://github.com/redis/redis-py/blob/15f315a496c3267c8cbcc6d6d9c6005ea4d4a4d5/redis/lock.py#L155

* Improve `requests/models` annotation

Source code here: https://github.com/psf/requests/blob/d718e753834b84018014a23d663369ac27d1ab9c/requests/models.py#L653

stdlib/turtle.pyi

@@ -1,5 +1,6 @@
+from _typeshed import Self
 from tkinter import Canvas, Frame, Misc, PhotoImage, Scrollbar
-from typing import Any, Callable, ClassVar, Sequence, TypeVar, Union, overload
+from typing import Any, Callable, ClassVar, Sequence, Union, overload
 
 # Note: '_Color' is the alias we use for arguments and _AnyColor is the
 # alias we use for return types. Really, these two aliases should be the
@@ -215,8 +216,6 @@ class TPen:
     st = showturtle
     ht = hideturtle
 
-_T = TypeVar("_T")
-
 class RawTurtle(TPen, TNavigator):
     screen: TurtleScreen
     screens: ClassVar[list[TurtleScreen]]
@@ -227,7 +226,7 @@ class RawTurtle(TPen, TNavigator):
     def setundobuffer(self, size: int | None) -> None: ...
     def undobufferentries(self) -> int: ...
     def clear(self) -> None: ...
-    def clone(self: _T) -> _T: ...
+    def clone(self: Self) -> Self: ...
     @overload
     def shape(self, name: None = ...) -> str: ...
     @overload
@@ -272,7 +271,7 @@ class RawTurtle(TPen, TNavigator):
     def end_poly(self) -> None: ...
     def get_poly(self) -> _PolygonCoords | None: ...
     def getscreen(self) -> TurtleScreen: ...
-    def getturtle(self: _T) -> _T: ...
+    def getturtle(self: Self) -> Self: ...
     getpen = getturtle
     def onclick(self, fun: Callable[[float, float], Any], btn: int = ..., add: bool | None = ...) -> None: ...
     def onrelease(self, fun: Callable[[float, float], Any], btn: int = ..., add: bool | None = ...) -> None: ...