split labels configurations add more prow commands

[mmorel-35]

Thank you for contributing to Velero!

Please add a summary of your change

• split actions/labeler and jpmcb/prow-github-actions configurations
• add more PROW commands

Does your change fix a particular issue?

Fixes #(issue)

Please indicate you've done the following:

• [x] Accepted the DCO. Commits without the DCO will delay acceptance.
• [x] Created a changelog file or added /kind changelog-not-required as a comment on this pull request.
• [ ] Updated the corresponding documentation in site/content/docs/main.

[mmorel-35]

/kind changelog-not-required

[mmorel-35]

Hi @blackpiglet,

It seems that actions/labeler and jpmcb/prow-github-actions configurations are incompatibles as kind is generating an error on actions/label execution.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 58.66%. Comparing base (3cbf2eb) to head (3650337). Report is 5 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #7776 +/- ## ======================================= Coverage 58.65% 58.66% ======================================= Files 344 344 Lines 28730 28731 +1 ======================================= + Hits 16853 16854 +1 Misses 10448 10448 Partials 1429 1429 ```

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[kaovilai]

Hi @blackpiglet,

It seems that actions/labeler and jpmcb/prow-github-actions configurations are incompatibles as kind is generating an error on actions/label execution.

Per their doc, it never meant to be the same file.

[blackpiglet]

I agree with @kaovilai. I also made some changes in PR #7775.

[mmorel-35]

Hi @blackpiglet ,

I integrated those changes here so it's clearly separate the concern of each PR.

[mmorel-35]

Anyone can second approve to merge this, so #7784 can then be rebased ?

[blackpiglet]

/cc @qiuming-best @Lyndon-Li