Archive and prune the github repo.

[charris]

The numpy repository has gathered a lot of maintenance branches that are no longer used. This is beginning to make such simple tasks as basing backports on the current release branch cumbersome due to the large number of branches listed in the base, and this also makes the choice subject to errors. I propose that we figure out how we want to save the history in an accessible way, yet unclutter the main repo. Searching on that topic shows several ways to do this, none of which look very appealing at first glance. Does anyone have experience with this or suggestions?

[charris]

https://stackoverflow.com/questions/1307114/how-can-i-archive-git-branches looks like one way to do this.

[seberg]

The way I read that is that we replace the branches with tags so that the branch list gets short (and the tag list is huge anyway)? That seems good to me, unless someone has another thought.

[rgommers]

This removes branch protection from the maintenance branches. Tags are easy to move and delete. So I'd prefer to not do this I think.

I think there's also not really an issue as far as I can tell, beyond scrolling down to the 28th branch when opening a backport PR? 28 branches really is very little (example of when it is bad: PyTorch has 6,925 branches in its repo).

[seberg]

No opinion from me either way really. Just commenting that I just saw that github has a beta for tag protection rules (and we would limit it to branches that only run on EOL Python versions).

[seberg]

FWIW, I added a tag protection that should trigger for any version tag. Although, it seems it just limits the number of users who can create/remove tags a lot (which also means it shouldn't disrupt any workflow, though).