Fix typehint of :meth:.Scene.restructure_mobjects. (#3902)

Author: fogsong233

manim/scene/scene.py

@@ -52,7 +52,7 @@
 from ..utils.iterables import list_difference_update, list_update
 
 if TYPE_CHECKING:
-    from collections.abc import Iterable
+    from collections.abc import Iterable, Sequence
     from typing import Callable
 
 
@@ -620,7 +620,7 @@ def remove_updater(self, func: Callable[[float], None]) -> None:
 
     def restructure_mobjects(
         self,
-        to_remove: Mobject,
+        to_remove: Sequence[Mobject],
         mobject_list_name: str = "mobjects",
         extract_families: bool = True,
     ):