String dtype: deprecate the pyarrow_numpy storage option

[jorisvandenbossche]

xref #54792

This old string alias "string[pyarrow_numpy]" is being deprecated for just "str" or the explicit pd.StringDtype("pyarrow", na_value=np.nan)

Directly using FutureWarning (it was an experimental opt-in, so not many people will already have been using it, and then we can directly remove it in pandas 3.0)

[mroeschke]

Thanks @jorisvandenbossche

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

git checkout 2.3.x
git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

git cherry-pick -x -m1 1908f2eb962e5c8b84483a6f0582b5e32b6f0ee8

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

git commit -am 'Backport PR #60152: String dtype: deprecate the pyarrow_numpy storage option'

4. Push to a named branch:

git push YOURFORK 2.3.x:auto-backport-of-pr-60152-on-2.3.x

5. Create a PR against branch 2.3.x, I would have named this PR:

"Backport PR #60152 on branch 2.3.x (String dtype: deprecate the pyarrow_numpy storage option)"

And apply the correct labels and milestones.

Congratulations — you did some good work! Hopefully your backport PR will be tested by the continuous integration and merged soon!

Remember to remove the Still Needs Manual Backport label once the PR gets merged.

If these instructions are inaccurate, feel free to suggest an improvement.

[jorisvandenbossche]

Manual backport -> #60173