Update to Python 3.14

[rhugonnet]

Python 3.14 releases next week!

We at least need to make our environment open to it (change the max pin). For CI, we test in an open PR, might have to give it a bit longer so that things fall into place (but with all the pre-releases, most major packages should have done the work already).

@belletva @adebardo Do we need to keep Python 3.10 in CI? We'll be testing 5 versions at once. FYI @adehecq

[belletva]

Yes we absolutely need to keep Python 3.10, in our side all our softwares (CARS, PANDORA, SLURP) are working only with Python 3.10!

[rhugonnet]

OK! 🙂