Update Python versions in test matrix

[llimeht]

With Python 3.14 released, it's time to look at getting new versions into the test matrix.

This PR:

• drops Python 3.10 which is very close to end of life (and likely EOL before the next sasmodels release)
• adds Python 3.13 and the tests pass
• adds Python 3.14

This PR is marked as a draft until...

• ruff is fixed (and the first change in the PR can be dropped
• adds Python 3.14 which currently fails, looking for a new pyopencl, which is to be expected (and maybe other packages)

We can periodically rerun this to see how progress towards 3.14 is going; we might do the top two items anyway at this stage.

EDIT: pyopencl wheels for 3.14 are now available and CI passes, so this is ready to be merged.