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

just merged a patch for this so can close this? i think so, master is passing now (or at least last couple of PRs) by https://github.com/pandas-dev/pandas/pull/37048