Add ubuntu 24.04 (tkn)

[tknerr]

Notes / TODO:

• arm64 build for 2404 base image still failing -- works locally, but takes reaaaaallly long to build compared to 2204 arm64 image
  • Suspicion is that something is odd with apt dependencies for the arm64 image
  • yet to be fixed
• when trying to update to a new runner machine (2204 or 2404) vagrant was not able to start the arm64 images at all.
  • Maybe this could help:
    • https://circleci.com/blog/building-docker-images-for-multiple-os-architectures/
    • https://github.com/namiops/circleci-multiarch/blob/main/.circleci/config.yml
• when trying to update to vagrant 2.4.9, some stdout messages seem to have changed, so we need to adapt tests accordingly (e.g. when expecting for successful box import)