Add ubuntu-24.04 to CI runners and bump publish-RepoSense runner

[gok99]

What feature(s) would you like to see in RepoSense

Add ubuntu-24.04 to CI runners and start using it to deploy reports in publish-RepoSense.

Is the feature request related to a problem?

The ubuntu-latest runner appears to be gradually migrating to ubuntu-24.04 runners. Due to Ubuntu 24.04 specific package manager configuations we had a failing pip install which broke publish-RepoSense. (#2249)

If possible, describe the solution

Let's:

• Add ubuntu-24.04 to the set of CI runners, replacing ubuntu-20.04.
• Bump the runner to ubuntu-24.04 in publish-RepoSense and update CI-scripts to use venv (see: GitHub Actions failing due to pip error #2249 (comment))