DEPR: automatic alignment on frame.__cmp__(series)
- [ ] closes #xxxx
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry

xref #28759, may close it depending on if we want to do anything else on that front
rebased+green