DOC: Added docstring to Timestamp.tzinfo
Follow up on #59458

Added docstring to `Timestamp.tzinfo`. Emphasized that `Timestamp.tz` is preferred due to its Pandas-specific functionality. Sections added are as follows:
- Summary
- Extended Summary
- See Also
- Examples

Removed `Timestamp.tzinfo` from code_checks.sh

- [ ] closes #59458 (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
- [x] 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.

Sorry, it appears a contributor already opened a PR a few days ago to address this issue in https://github.com/pandas-dev/pandas/pull/61100 that was merged.

Closing this PR as solved, but happy to have more PRs!