Filter out obsolete distro releases

This is a follow-on to Implement mage pulp:supportedOSVersions target (!6024 - merged)

Using EOL distros from https://endoflife.date, I've added all distro releases that are currently fully EOL. If paid long-term support is available for a release, I've not included it here. paid support is only really applicable to "enterprise" distros like Ubuntu, RHEL and SLES. The rationale is that folks using these distros may have paid for LTS, and would damn well expect runner to still be available for a paid LTS release.

Wait, why is this even necessary? In Implement mage pulp:supportedOSVersions target (!6024 - merged) we said we'd push all this "logic" to the pulp config itself, which we did in https://gitlab-org/build/pulp-repository-automation/-/merge_requests/5+.

Well, it turns out it is advantageous to keep all the distro release we've ever pushes a runner package to in that config file, and @balasankar plans to revert https://gitlab-org/build/pulp-repository-automation/-/merge_requests/5+, so we will have to filter out EOL releases here after all.

The net result of this is that when @balasankarc reverts https://gitlab-org/build/pulp-repository-automation/-/merge_requests/5+, the list of distro/versions produced by mage pulp:supportedOSVersions should not change.

Unlike the analogous code for packagecloud, which uses skipRelease and oldestRelease, here I've only used skipRelease since it gets the job done.

Closes https://gitlab.com/gitlab-org/gitlab-runner/-/work_items/39143+