chore: ci: bump VM to Ubuntu 24.04 image

[dtrudg]

Description of the Pull Request (PR):

Update CI to use the Ubuntu 24.04 VM image.

This requires adding an apparmor configuration file to permit use of unprivileged user namespaces.

Before submitting a PR, make sure you have done the following:

• Read the Guidelines for Contributing, and this PR conforms to the stated requirements.
• Added changes to the CHANGELOG if necessary according to the Contribution Guidelines
• Added tests to validate this PR, linted with make check and tested this PR locally with a make test, and make testall if possible (see CONTRIBUTING.md).
• Based this PR against the appropriate branch according to the Contribution Guidelines
• Added myself as a contributor to the Contributors File

[cyanezstange]

This LGTM, thanks