BLD: Fix pydata-sphix-theme version GH45374
- [x] closes #45374 
- [ ] tests added / passed
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit) for how to run them
- [ ] whatsnew entry

@jorisvandenbossche should we backport this? changing milestone to 1.4.1 @meeseeksdev backport 1.4.x Something went wrong ... Please have a look at my logs. (sidenote: if we don't use the dev version from git anymore, we can probably move it to the conda packages section of the file)