Configure isort to follow black formatting conventions

[KevinJBoyer]

Ticket

n/a

Changes

• Configure isort to follow black formatting conventions

Context for reviewers

• Without this change there are situations where isort's formatting conflicts with blacks, leading make format-check to fail even after make-format

Testing

You can see an example file that will fail without this change at this PR: navapbc/labs-referral-pilot#11

[doshitan]

Looks good. I'd rather switch to ruff formatting instead of black+isort, but good to improve the existing stuff where easy.

Can drop the redundant settings before merge.