Modify allocation process of the PhysicalBoneSimulator in Skeleton3D

[TokageItLab]

• Fixes Crash when re-importing a GLB file which is used in currently edited scene. #91063
• Fixes Irreversible broken Skeleton3D in editable children but new instances looks fine #91211

Fixed an issue with the allocation process with PhysicalBoneSimulator as virtual children that was occurring when Skeleton3D was added to or removed from scenes in the editor, such as ImportScene.

[clayjohn]

Won't this result in a memory leak on exit since the simulator is never freed?

[TokageItLab]

As long as it is guaranteed to be add_child() immediately after allocating, I think it is guaranteed that memory will be released when removing Skeleton from the scene or when remove_child(simulator) is done (unexpectedly).

[akien-mga]

Thanks!