Remove explicit __init_subclass__ type hints

Instead, fall back to the `object.__init_subclass__` definition.

Author: QuLogic

lib/matplotlib/artist.pyi

@@ -28,7 +28,6 @@ class _Unset: ...
 
 class Artist:
     zorder: float
-    def __init_subclass__(cls): ...
     stale_callback: Callable[[Artist, bool], None] | None
     figure: Figure | SubFigure | None
     clipbox: BboxBase | None

lib/matplotlib/patches.pyi

@@ -319,7 +319,6 @@ def draw_bbox(
 ) -> None: ...
 
 class _Style:
-    def __init_subclass__(cls) -> None: ...
     def __new__(cls, stylename, **kwargs): ...
     @classmethod
     def get_styles(cls) -> dict[str, type]: ...

lib/matplotlib/transforms.pyi

@@ -181,7 +181,6 @@ class Transform(TransformNode):
     # Implemented as a standard attr in base class, but functionally readonly and some subclasses implement as such
     @property
     def has_inverse(self) -> bool: ...
-    def __init_subclass__(cls) -> None: ...
     def __add__(self, other: Transform) -> Transform: ...
     @property
     def depth(self) -> int: ...