Fix type hints for Legend.bbox_to_anchor

Author: QuLogic

lib/matplotlib/legend.pyi

@@ -128,7 +128,12 @@ class Legend(Artist):
     draw_frame = set_frame_on
     def get_bbox_to_anchor(self) -> BboxBase: ...
     def set_bbox_to_anchor(
-        self, bbox: BboxBase | None, transform: Transform | None = ...
+        self,
+        bbox: BboxBase
+        | tuple[float, float]
+        | tuple[float, float, float, float]
+        | None,
+        transform: Transform | None = ...
     ) -> None: ...
     @overload
     def set_draggable(