TST: dropping of nuisance columns for groupby ops #38815
Add more aggregation functions for nuisance tests

- [ x] closes #38815
- [x ] tests added / passed
- [x ] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit) for how to run them
- [ ] whatsnew entry
