next channel?

[StefanKarpinski]

After a new release branch has been cut but no alphas have been released it's a little strangely difficult to get that version via juliaup. E.g. right now this is Julia 1.12. I can do juliaup add 1.12-nightly but I'll have to do that every time there's a new release branch. How about having a channel called next which points to the version that will become the next release?

It would also be nice if you could refer to unreleased versions with the x.y channels, so even though there's no 1.12 release yet, I could do juliaup add 1.12 now and get 1.12-nightly and later when there are actual 1.12 releases the channel will point to those.