Fix np.MachAr warning matching in test.

[sklam]

Somehow #9347 changed the behavior of the filter.
The invisible characters from termcolor highlight now matters. But comparing the warning message before and after that PR does not reveal any visible difference.

Also added a simplefilter("ignore") to suppress any warning config from PYTHONWARNINGS in the python process.

[sklam]

To test this, make sure the environment has colorama and NUMBA_DISABLE_ERROR_MESSAGE_HIGHLIGHTING is cleared.

Run: NUMBA_DISABLE_ERROR_MESSAGE_HIGHLIGHTING= SUBPROC_TEST=1 python runtests.py -k test_np_MachAr_deprecation_np122 -v

[sklam]

BFID: numba_yaml_423

[stuartarchibald]

Thanks for fixing this @sklam. I debugged this a bit, AFAICT the actual strings in the message are the same, what I think is changing is what happens internally as part of the matching process, now the Numba warnings inherit from the standard library warnings the way the message strings are normalized internally is different:
https://github.com/python/cpython/blob/e0c6995b4fa9803a886fe1d88d6a9aec166a99e8/Python/_warnings.c#L657-L674

[stuartarchibald]

Thanks for the patch. I tested main manually against the reproducer in #9362 (comment) and the test fails, application of this patch then makes it pass. The changes also make sense with respect to some debugging I did #9362 (comment).

[sklam]

CI passed and enough buildfarm config has passed (e.g just windows ones are taking a long time and we don't want to wait for it)