gitlab-ci: drop Fedora 35 and earlier, Debian 9

All of these are EOL, most of them by quite a bit.

Since this regenerates the containers we're now running into a problem with pip install on Debian. pip on Debian 12 semi-forces us to use a venv. That's hard enough but even more so when we just want to run meson which only relies on the standard library anyway.

Since that flag doesn't exist on earlier versions, try both and hope one invocation succeeds.