commits: c6685820247d4d22e7a3e6fe9700fe2bdadcc361

This data as json

sha	message	author_date	committer_date	raw_author	raw_committer	repo	author	committer
c6685820247d4d22e7a3e6fe9700fe2bdadcc361	Fix .groupby(multi index level) (#7830) * Fix .groupby(multi index level) Closes #6836 * Update xarray/tests/test_groupby.py * mypy: Add _DummyGroup.to_index --------- Co-authored-by: Illviljan <14371165+Illviljan@users.noreply.github.com>	2023-06-06T00:21:31Z	2023-06-06T00:21:31Z	0c7e9e762dbfd6554e60c953bf27493047d95109	cd792325681cbad9f663f2879d8b69f1edbb678f	13221727	2448579	19864447