BUG: fix convert_dtypes to preserve timezone from tz-aware pyarrow timestamp dtype
Removed if statement blocks that were causing timezone to be removed, added a test to confirm that bug is fixed, and added BUG fix to 3.0.0 documentation.
Fixes issue in #60237 

pre-commit.ci autofix Hi all, apologies for so many commits to this PR, this is my first issue and I'm not that familiar with GitHub so I was learning as I went. I believe I've fixed the timezone preservation issue and my test case passes for the minimum version unit test as well now. Let me know if you see any issues that need to be addressed though! Thank you for your help!

Fix for #60237  This pull request is stale because it has been open for thirty days with no activity. Please [update](https://pandas.pydata.org/pandas-docs/stable/development/contributing.html#updating-your-pull-request) and respond to this comment if you're still interested in working on this. Thanks for the pull request, but it appears to have gone stale. If interested in continuing, please merge in the main branch, address any review comments and/or failing tests, and we can reopen.