Description

Lucene issues stable releases via backporting.

But the backporting is a manual git cherry-pick of the committer: maybe they run all tests, maybe some, maybe not.

It would be nice, for the reliability of stable releases, to instead allow the pusher to "label" the PR to indicate a backport. When the PR with such a label is merged, it is backported by a bot: it can e.g. open a backport PR.

With this approach we make it easy, yet also enforce certain safeguards, such as all checks passing.

Currently the PR merges in github are all squash merges, for backporting I think it would cause undue conflicts, change this flow to use ordinary git merge.

Also I'm worried about CHANGES.txt, which is conflict-central, but that can be solved in other ways.

Way down the road:
Maybe we even allow backport to just go in, if all checks pass? or maybe require a different label trivial-backport for that. The pusher asked for it. Its just saving time.