This seems to be the "HEAD" of this change, https://github.com/Perl/perl5/tree/fa598077fe27c24ed6dc2cd93e94036b1b9f5793. Fork the perl5 repo, checkout that SHA, create a branch, then push to your remote. A tag may work, also - you should also conult this file to make sure it gets triggered on your own remote as you expect, https://github.com/Perl/perl5/blob/fa598077fe27c24ed6dc2cd93e94036b1b9f5793/.github/workflows/testsuite.yml - plus you can tweak it as you wish.

That said, rjbs has been on a tear cleaning up branches on the upstream remote that should be primarily on personal forks. So xenu may have one, idk. HTH