Otherwise it'll get invoked in later test cases. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2417>
Avoids a couple of singleton accesses. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2417>
Add a test that uses vkms to test that mode setting works, and that rendering works. It renders 10 frames in a row after mode setting, then exits. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2151>