[MRG] Fix nightly build

[aaronreidsmith]

Description

This PR fixes the nightly build by removing the use of pytest.warns(None) since it has been removed in pytest 8. It also bumps the Python version for nightly to 3.12

Type of change

• Bug fix (non-breaking change which fixes an issue

How Has This Been Tested?

• Nightly tests work no

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes