From my quick look, rebasing to 0.61.4 is probably the lowest friction point, without python versions getting problematic.

As I've mentioned on the Slack it's not trivial at all to rebase Meson - actually it's trivial if one doesn't care about the packages that are using Meson - see how it went in RHEL 9 where we've rebased Meson and we already had to fix 4 additional packages so they don't start to fail to build from source after the rebase - https://bugzilla.redhat.com/show_bug.cgi?id=2022729#c8 and https://bugzilla.redhat.com/show_bug.cgi?id=2022729#c10. And I'm more worried how the situation will look like with even older packages that we have in RHEL 8. I'm tempted to decline this request, but let's see whether Dave will find a way around this.

I've given up on this plan, I included a version of meson into the mesa build to get around it.