When we pick the frame clock given the associated actor, that frame
clock in fact comes from a picked actor. In order to not end up with
stale frame clocks, which may happen on e.g. hotplugs, monitor layout
changes, or non-optimal frame clocks, which may happen when the parent
used for picking the clock moves to another view, lets listen to
'stage-views-changed' on the actor used for picking the clock too.
Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/1327https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1404
06c4841e22