Add Mac and Windows to CI

[rhugonnet]

Summary

This PR adds Windows and Mac to the full test suite run during CI. We now have 9 jobs running in CI (Python 3.8, 3.9 and 3.10 for Ubuntu, Windows and Mac).
All core functionalities are working, however a couple little issues remain, opened for later work: making outputs of SciPy fully consistent between OS due to floating point considerations, making Sphinx work on all OS, and making PROJ work on Windows to use proj-data grids.

In details

This PR:

• Unsets the PROJ_LIB variable during CI to allow rasterio to import correctly, otherwise failing on Windows. This fix is recommended by https://rasterio.readthedocs.io/en/latest/faq.html#why-can-t-rasterio-find-proj-db-rasterio-from-pypi-versions-1-2-0. Curiously, this is not needed in GeoUtils' CI, I couldn't figure why it fails in xDEM exactly (similar environments);
• Performs rounding of the results of scipy.optimize.least_squares after setting a lower xtol to ensure the optimized parameters found are the same between OSs. This works to get the exact same output of NuthKaab() co-registration on Windows and Linux, but somehow still differs on Mac... Added a comment on this in issue Fix results of scipy.optimize between OS #310.
• Tries to do the same rounding operation for scipy.optimize.basin_hopping but the xtol parameter does not exist as such, we would need to derive the tolerance of the parameter from the scipy method and ftol or gtol parameters, opened issue Fix results of scipy.optimize between OS #310;
• Skips tests related to grids stored by proj-data in test_dem.py on Windows, that currently can't be found, opened issue PROJ grids not found on Windows #311;
• Skips the building of the documentation with Sphinx that fails on both Mac and Windows with the same TypeError: 'module' object is not callable when xdem.examples.get_path() is called, notably in examples/*/plot_*.py scripts for sphinx-gallery, opened Sphinx fails when building on Mac or Windows #316.

Unrelated but needed to fix bugs related to package updates, this PR:

• Forces the version of openh264 in environment.yml at 2.3.0 (on which opencv depends), as it started failing with 2.3.1 on 24.09.22 (probably an erroneous release from them...), opened Remove fixed version of openh264...  #317;
• Upgrades pre-commit hooks to solve a mypy issue with the latest Python 3.10 version: Positional-only parameters with python 3.10.7 (and numpy) (fixed in 0.981) python/mypy#13627;
• Updates the regex pattern to catch RuntimeWarning with true_divide, as those can be simply called divide now.

Resolves #126

[adehecq]

Haha, I see some failure on Windows 😆

[rhugonnet]

One issue closed, four open! But at least now we know that all the important stuff works as intended on all OSs! 🥳

Ready to merge, then I'll add the cache in xDEM to speed up CI, that can take up to 30min right now...

[adehecq]

Looking good !
CI will take even longer now, but hopefully the cache will speed things up.

[rhugonnet]

Merging as there's only two comments added in the code since the last approval