ci(sync-labels): Create sync-labels.yml workflow

[davorpa]

What does this PR do?

Improve repo

For resources

Description

• Using a wide used crazy-max/ghaction-github-labeler action
• Save current repository labels in a file
• Monitor this file to auto import labels to the repo.
• Having a manual way to run it with granularity over input parameters (test and deletions)
• If a PR is open test CRUD, if merged... do modifications but without deleting any label (the least destructive action)

Why this?

Allows to collaborators add manage the repo labels having the last desision whom have write permissions.

E.g. add the labels of new locale (see #7024 (comment))

Dry-run over this repository: https://github.com/EbookFoundation/free-programming-books/runs/8230716302?check_suite_focus=true#step:3:218

Checklist:

• Read our contributing guidelines.
• Used an informative name for this pull request.

Follow-up

• Check the status of GitHub Actions and resolve any reported warnings!

[eshellman]

I don't understand the problem this is trying to address.

[davorpa]

I don't understand the problem this is trying to address.

Sorry if I can't explain it better in english

See Why this? section. One more...

• Have same repo labels in forks than in upstream repo

[eshellman]

this appears to have created 4 new checks. This will tend to obscure the checks we want people to pay attention to. It's a feature that adds complexity and maintenance burden for the benefit of only a small number of maintainers. I think a better course would be to reduce the number of labels to something that can more easily managed by hand. The fact that you feel a need for automation to manage the labels suggests that there are too many labels!!

[davorpa]

I understand 👍 . Let's keep it simple!

It was only an idea to start to triage resources using labels.

The reason I added the locale labels in the past was for classifying resources, and if someone want to susbcribe to this files changes, e.g. a mantainer in charge of review PRs of this country/language, they have a way to use filters. Obviously, the second part is not developed yet (extract locale slug from files and do the label triage #7024 (comment)).

But maybe #7024 (comment) would be a better aproach to group resources by locale and mantain files low sizing. A big breaking change for us that needs coordination!!

this appears to have created 4 new checks...

Acording to on events these checks only appears if any of both files (labels.yml, sync-labels.yml) change!

I have this other workflow if only one job (or whatever you call "check") and 4 steps if is needed in a future.

davorpa/testing-github-actions@4722aba#diff-a877ed9f27d115d95934fd904f2475dcec6ce4125da686dd5b3c75a696fff1c6R4-R10

Some workflow runs at:

• https://github.com/davorpa/testing-github-actions/actions/runs/3012994861 for sync labels
• triggered by commit davorpa/testing-github-actions@4578cbb which autoadd a label needed by my stale workflow
• More at https://github.com/davorpa/testing-github-actions/actions.

Feel free to take a look.

Said that.... next workflow: auto-conflicts 🚀