Unpin Python version in the development environment

[datapythonista]

xref #61555

Our base conda environment environment.yml is used locally by pandas developers (contributors and maintainers), and for some CI jobs, like building the documentation. For stability, we pinned the version of Python to a specific version (currently python=3.10). As new versions of Python are released, this is becoming outdated, and for no particular reason we're now going building our docs and creating our development environments in a Python version soon to stop being supported.

This issue is to remove the pin, leave python open to any version, which in general it should be the latest available, and fix all the problems in the CI caused by upgrading the version here.

The errors detected when upgrading can be found here:

• https://github.com/pandas-dev/pandas/actions/runs/15452252618/job/43496928413?pr=61555
• https://github.com/pandas-dev/pandas/actions/runs/15452252597/job/43496928225?pr=61555

[rhshadrach]

If we don't pin to the minimum supported version, I fear contributors will submit code that is only supported on higher versions and then have to debug-via-CI. That is not a good experience.

I think we should continue to push contributors to use the minimum Python version by pinning it rather than removing the pin.

[datapythonista]

Thanks for the feedback @rhshadrach. Personally I think the CI will prevent any issue, and I'm not sure how often people code things that only work in the latest versions of Python. At the same time, it's not a big deal to keep updating the Python version in environment.yml, and probably not so important to run sphinx, the website, pre-commit, and not sure if something else in a newer Python version either. I'd still remove the pin, but I'm ok to just upgrade to 3.11 if you think it does make a difference regarding the contributors.

[rhshadrach]

I've lost track - when are we dropping 3.10 support? Do we have discussion on this?

[datapythonista]

#60059 and Matt mentioned it in the last dev call too

[rhshadrach]

Thanks! I'm good with pinning the environment to 3.11 in that case even before we drop 3.10 fully on main. But I do think we should prefer this over no pin.