DEPS: Make pytz an optional dependency
- [ ] closes #34916 (Replace xxxx with the GitHub issue number)
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [ ] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.


This makes pandas return `zoneinfo.ZoneInfo` objects by default from string inputs
might be easier to break into steps e.g. one PR just changing which UTC, one just changing FixedOffset, then the hard one for the general case. > one PR just changing which UTC, one just changing FixedOffset

These are already changed (I think you changed it for 2.0), so now this is tackling the general case. Closing in favor of https://github.com/pandas-dev/pandas/pull/59089