paint the nightly ci green - misc changes to get things in a good state ahead of the branchpoint

Based on the latest nightly pipeline: https://gitlab.freedesktop.org/mesa/mesa/-/pipelines/1227805

This excludes https://gitlab.freedesktop.org/mesa/mesa/-/jobs/61243935 a660_vk_full 2/3 which I don't know how to fix; I expect a specific test/test group is hanging the gpu, but I don't know how to find out which one, so I just let that one go.

With this, everything (except a660_vk_full 2/3) should be green on the next nightly 💚