nix-update does not work with tags

[JohnRTitor]

I am glad that there is a tag attribute now and r-ryantm is now auto replacing refs/tags/${version}, but this largely breaks nix-update-script as nix-update-script does not yet have support of tag. Upstream issue: Mic92/nix-update#304

This largely breaks auto update as a lot of packages rely on nix-update.

So can we just fix this or hold off any treewide change replacing rev = refs/tags with tag?

CC: @Atemu @Mic92

[Atemu]

Someone just needs to PR a fix. Holding off a treewide until that's done sounds like a sane idea to me. As mentioned previously, there isn't any great urgency to migrating to tags and waiting for stuff like this is something we should absolutely do.

I should perhaps communicated that clearer but the purpose of the initial PR was to establish the concept as an alternative to boilerplate that we should prefer, not to immediately roll it out as a breaking change.

[GaetanLepage]

Fixed by #370820.