ci(backport): test workflow

[rami3l]

Part of #4738.

This PR adds a joke to the README.

[djc]

I'm not that into it. But if someone else likes it, I can live with it.

[rami3l]

@djc This change is explicitly made absurd to test the backporting workflow (so that you will never merge it by accident into trunk, see the branch name and the target branch), don't panic XD

[rami3l]

One special thing about this PR is, of course, it has neither "enqueue" nor "wait for approval" options. I was just reminded that those will only appear in the PRs created after the branch rule modifications, so maybe I'll need to adjust the checklist a bit...

@Kobzol Speaking of #4738, could we have the merge queue enabled for release/* branches gated on the conclusion job just like we do now with main, but without any branch protection rules/approval requirements (yet)? Such modifications will be very useful in the testing phase.

[rami3l]

conclusion passed perfectly, the pre-enqueue jobs are identical to regular PRs targeting main.

[rustbot]

This PR was rebased onto a different release/1.29-dummy commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[Kobzol]

@Kobzol Speaking of #4738, could we have the merge queue enabled for release/* branches gated on the conclusion job just like we do now with main, but without any branch protection rules/approval requirements (yet)? Such modifications will be very useful in the testing phase.

Technically you need a branch protection or a ruleset to enable a merge queue, but that doesn't mean that you also must configure approval requirements, so yes, that should be possible.

[rami3l]

Technically you need a branch protection or a ruleset to enable a merge queue, but that doesn't mean that you also must configure approval requirements, so yes, that should be possible.

@Kobzol Cool. What is the absolute minimal branch protection we can enable in order to get the queue going? Can we try that on release/* branches first? Many thanks in advance 🙏