ClutterRedrawFlags are a way to give Clutter additional context
about what it needs to redraw. There currently is only one flag defined,
CLUTTER_REDRAW_CLIPPED_TO_ALLOCATION, this flag would clip the redraw to
the actors current allocation.
Since ClutterActor also provides the clip_to_allocation property (which
affects the paint volume of the actor instead of only one redraw), the
additional CLIPPED_TO_ALLOCATION flag seems unnecessary. It's also only
defined to be used privately in Clutter, which it never is, so let's
remove it.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1527
8b21fb4f96