ci: split branch and PR workflow to allow auto merge

[acolombier]

Since GH has no ability to specify which even is required for a required actions and skipped actions are considered successful (:grimacing:), this aims to restore auto-merge capability to using to explicit workflow for branch and PR, and remove the "Ready for merge" from the branch workflow

Some reference:

Screencast.From.2026-01-08.18-56-00.mp4

[daschuer]

OK, let's try it. Thank you.

[daschuer]

The CI of this branch does not run. I have tried to edit the initial post as usually, but it does not restart the CI.

[acolombier]

I believe this is because it isn't merged yet - Actions will get created when merging, so right now the pull_request event didn't register yet. You should be able to test it in your fork

[daschuer]

Tested in my private repository and got:

 Invalid workflow file: .github/workflows/pr.yml#L1
(Line: 20, Col: 9): Job 'pre-commit' depends on unknown job 'stop-build'., (Line: 27, Col: 9): Job 'checks' depends on unknown job 'stop-build'., (Line: 35, Col: 9): Job 'build' depends on unknown job 'stop-build'., (Line: 46, Col: 9): Job 'ready' depends on job 'pre-commit' which creates a cycle in the dependency graph., (Line: 47, Col: 9): Job 'ready' depends on job 'checks' which creates a cycle in the dependency graph., (Line: 49, Col: 9): Job 'ready' depends on job 'build' which creates a cycle in the dependency graph.

https://github.com/daschuer/mixxx/actions/runs/19197911532

[daschuer]

Is this a real issue?

[acolombier]

It is.
Try to enable auto-merge on a recently pushed sync branch PR, approve it, and see it being merged instantly, before the Required action complete.
I'll share a recording next I see one to capture some evidence of why this change is necessary.

[daschuer]

My question was regarding my test results in #15500 (comment)
Can you explain why it happens? Does it need to be fixed?

[acolombier]

Ah sorry - indeed, this was an issue. Reference to stop-build were left over in the PR workflow. Should be clean now!
Edit: I amended the commit directly.

[acolombier]

On second thought, I think we also have the issue of GH considering skipped as successful, so I think both this fix and Ready to merge refactor in #14360 are necessary