Linkchecker blocks merging when certificate on external site is expired

[konstin]

Issue Description

We currently can't merge any changes because the certificate of someone's private blog expired: https://github.com/pypa/packaging.python.org/actions/runs/21515206224/job/61995726370. As the linkchecker checks all sites for each PR, it has a lot of opportunities to fail in way unrelated to the PR it's checking. For example, the PR the linked workflow it's failing on is trying to handle another failure caused by a sourceforge policy change: #1997.

Could we move the link checker to not be a required check, or move it to a daily cron CI job? I can file a PR to do the change.

Code of Conduct

• I am aware that participants in this repository must follow the PSF Code of Conduct.

[woodruffw]

Yeah, fully agreed. IMO we can disable the link check on PRs but keep it as a periodic cron for maintenance purposes.

[woodruffw]

I've temporarily added that domain as part of #1997 as well.