regularization towards initial guess

[nicolearetz]

• regularization towards an initial guess (defaults to zero if none is provided) + tests
• expansion of operators to larger or smaller basis + tests
• fixed bug in Gram Schmidt algorithm in the method of snapshots
• parameterized polynomial operators of arbitrary order

Version now 0.5.17, GitHub Actions also modified to remove Python 3.9, add Python 3.14, and address a matplotlib issue with testing on Windows.

[shanemcq18]

I also need to track down why some of the tests are failing on GitHub, stay tuned.

[shanemcq18]

I need to track down an issue with one of the tests, but before that, I was getting some failures on old versions of Python on my local machine that seem to be related to this issue: numpy/numpy#29820. This hopefully shouldn't be a problem for our tests, but it's messing me up locally. It's time to drop python 3.9, so that might help things a bit...

Anyway, here's what actually needs to be fixed: test_initial_guesses() in tests\lstsq\test_tikhonov.py fails either on some systems or on some random draws when n_dofs = 1. Still investigating.

[shanemcq18]

Attempting to address the GitHub Actions issue with windows and Tcl (matplotlib backend).