Update formatting to match recent black version(s)

[phlogistonjohn]

Recently, local tox runs started finding black formatting issues that were not flagged before, most likely due to new release of the black tool.
There's a workaround present in PR #98 that avoids taking the newest versions. It would be good to remove this workaround and update the formatting (as long at it makes sense).

This issue is a reminder to get that done.