Build upstream version 1.2.0 for the CI image if needed.
v2:
* Build upstream 1.2.0 tag instead of 1.2.2.
v3:
* Build upstream 1.2.3 tag for CI, it has a needed fix.
v4:
* Enable systemd support in pipewire build. (Jonas Ådahl)
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3876>