Enable flake8-pyi's Y037 (#9686)

stdlib/turtle.pyi

@@ -1,7 +1,7 @@
 from _typeshed import Self
 from collections.abc import Callable, Sequence
 from tkinter import Canvas, Frame, Misc, PhotoImage, Scrollbar
-from typing import Any, ClassVar, Union, overload
+from typing import Any, ClassVar, overload
 from typing_extensions import TypeAlias
 
 __all__ = [
@@ -133,7 +133,7 @@ __all__ = [
 # alias we use for return types. Really, these two aliases should be the
 # same, but as per the "no union returns" typeshed policy, we'll return
 # Any instead.
-_Color: TypeAlias = Union[str, tuple[float, float, float]]
+_Color: TypeAlias = str | tuple[float, float, float]
 _AnyColor: TypeAlias = Any
 
 # TODO: Replace this with a TypedDict once it becomes standardized.