Update Ubuntu image used by CI to ubuntu-latest

[reneSchm]

Motivation / Current Behaviour

We decided to temporarily downgrade to 22.04 in #1160 since 24.04 broke (some dependencies used by) the CI.

Enhancement description

• revert or undo changes by #1160
  • replace ubuntu-22.04 by ubuntu-latest
    • fix dependencies. maybe use branch try-fix-ci as a starting point.
  • add back PyQt6 to py-epidata dependencies
    • may be fix by specifying PyQt6-sip<13.9

Additional context

See the description of #1160 as well as CI runs for try-fix-ci starting on the 10.12.

Checklist

• [X] Attached labels, especially loc:: or model:: labels.
• [ ] Linked to project