ci: update ci pipeline and add python 3.12

[tmorrell]

❤️ Thank you for your contribution!

Description

Update CI to match other invenio repos and remove outdated requirements-builder. Includes changes from @mfenner from #91

Checklist

Ticks in all boxes and 🟢 on all GitHub actions status checks are required to merge:

• I'm aware of the code of conduct.
• I've created logical separate commits and followed the commit message format.
• I've added relevant test cases.
• I've added relevant documentation.
• I've marked translation strings.
• I've identified the copyright holder(s) and updated copyright headers for touched files (>15 lines contributions).
• I've NOT included third-party code (copy/pasted source code or new dependencies).
  • If you have added third-party code (copy/pasted or new dependencies), please reach out to an architect.

Reminder

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1. You license your contribution under the same terms as the current repository’s license.
2. You agree that you have the right to license your contribution under the current repository’s license.

[slint]

Small nit for the GitHub actions workflow, but otherwise it's good to merge

[fenekku]

I think I don't even bother with those anymore haha!