Add support for Python 3.14

[gdementen]

As of today (2025-12-03), most things work.

There are a few test failures though (tested on my local computer because the CI wouldn't run on 3.14 because of the missing pytables package). One that I already fixed in one of my branches for AxisCollection.index(). All the others are related to CheckedSession. @alixdamman : could you handle those? It's not urgent since this is not for version 0.35.

Before we can release larrayenv we will also need conda packages for pytables and xlwings, but this is out of our hands and we can already ready ourselves by fixing the other issues.

EDIT: As of today (2025-12-11), all issues are fixed, so we just need to wait for conda packages for pytables and xlwings.

FWIW, xlwings is easily pip installable (so I could already test that part) but pytables is not (it tries to compile from source, which fails on my machine) but I do not expect any failures on that front.

EDIT: As of today (2025-12-19), all issues are fixed and there is a package for xlwings, so we just need to wait for a conda package for pytables.

FWIW, pytables is not easily pip installable (it tries to compile from source, which fails on my machine) but I do not expect any failures on that front.

Targetting for 0.36 as I suppose the package will be available by then.