Bug groupby quantile listlike q and int columns
When columns are integers, `df.groupby(label).quantile(<arraylike>)` fails.

- [x] closes #30289
- [x] tests added / passed
- [x] passes `black pandas`
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry
