Since there are now no more allocation flags, we can remove ClutterAllocationFlags from Clutter. https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1245
In cogl use cogl-config.h and in clutter use clutter-build-config.h. We can't use clutter-config.h in clutter because its already used and installed. https://bugzilla.gnome.org/show_bug.cgi?id=768976