We recently had an issue where an anv merge failed due to a bug in zink, which validation would have caught. Get some coverage by default on the main branch. This increases runtime from 9:30 to 12:10. I don't feel good about this, but I've got https://gitlab.khronos.org/Tracker/vk-gl-cts/-/issues/4398 in flight to try to knock the time back down. Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22459>