update CI for python 3.12

[braingram]

3.x is now using python 3.12 (instead of python 3.11). This PR updates the CI to use python 3.11 for coverage and jwst jobs

As this PR changes require CI jobs the branch protection rules will need to be updated.

As this PR only changes CI configuration regression tests were not run.

Checklist

• [ ] added entry in CHANGES.rst (either in Bug Fixes or Changes to API)
• [ ] updated relevant tests
• [ ] updated relevant documentation
• [ ] updated relevant milestone(s)
• [ ] added relevant label(s)

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Files	Coverage Δ
src/stdatamodels/util.py	97.00% <100.00%> (+0.01%)	:arrow_up:

:loudspeaker: Thoughts on this report? Let us know!.

[braingram]

Thanks!