
Right now we damage the stage even if an actor is not mapped, for example in the overview. Stop doing so, reducing over-paint significantly in some situations. Clones will still do stage damage on their own. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2035> (cherry picked from commit 136caca5d51e0ac8ff5e7b79aca32d6da2306d4f)