These tests were written (and copy-pasted) before ClutterActor
had an actual background-color property. As a preparation to
the removal of ClutterRectangle, replace all these rectangles
with plain actors and background colors.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1332
This removes ClutterAnimation and related tests. ClutterAnimation has
been deprecated for a long time, and replacements exist and are used by
e.g. GNOME Shell since a while back.
This also disables a few relatively unrelated interactive tests, as they
rely on ClutterAnimation to implement some animations they use to
illustrate what they actually test.
As interactive tests currently are more or less untestable due to any
interaction with them crashing, as well as they in practice means
rewriting the tests using non-deprecated animation APIs, they are not
ported right now. To actually port the interactive tests, it needs to be
possible to fist interact with them.
https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1192
