TST: added test for groupby/apply timezone-aware with copy
- [x] closes #27212
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

added test for groupby/apply timezone-aware with copy

lgtm ping on green Thanks @jreback all checks are green. Thanks @sanders41! 