Bring back the `INSERTKEY_XYZ_TO_RGB` enum item for the `keyframe_insert()` function (it was removed in30b0c5b225). This way any Python code that targets Blender 4.x can safely pass this flag, without having to check specific Blender versions. Note that the flag is implemented as a no-op, as the behaviour change introduced in30b0c5b225(just looking at the user preference) is still retained. The purpose of this commit is simply to avoid the `ValueError` exception that would otherwise be raised. This should also fix Rigify report blender/blender-addons#105241. Pull Request: https://projects.blender.org/blender/blender/pulls/119625