ci: migrate to Ubuntu 24.04

[daniloegea]

Move to Ubuntu 24.04 and drop the workarounds that were needed to run the tests on 22.04.

Note: I mistakenly thought it was already available after finding some github action commits adding Noble to the list of runners. But it's still in the roadmap https://github.com/github/roadmap/issues/958

Description

Checklist

• [ ] Runs make check successfully.
• [ ] Retains 100% code coverage (make check-coverage).
• [ ] New/changed keys in YAML format are documented.
• [ ] (Optional) Adds example YAML for new feature.
• [ ] (Optional) Closes an open bug in Launchpad.

[slyon]

rebased.