Bump supported Python version to 3.12, 3.13 and 3.14

[pnuu]

Drop Python 3.11 support and add Python 3.14 to CI.

• Closes Drop Python 3.11 support when 3.14 is fully supported #3267

[pnuu]

Numba support is still missing. I'll see which features require it, or if it's an indirect requirement.

[pnuu]

The only place Numba is used directly in Satpy code is the GMS-5 VISSR L1b reader. And I guess HoloViews uses it as the hvplot tests have @skip_unstable_numba decorators in test_conversions.py.

[pnuu]

From numba/numba#9957 (comment)

The release schedule is currently as follows:

0.63.0 (which is currently being worked on and should become available in a few weeks) will support 3.14 and 0.64.0 (which does not yet have an ETA) will support free-threading.

[djhoese]

Haha that commment for numba is 2 weeks old. Anyway...if this passes before 0.60 is released, does this get included in 0.60 or is this one of the deprecations for 1.0?