lint with isort and then black

[aflaxman]

Title: lint with isort and then black

Description

• Category: lint
• JIRA issue: none
• Research reference: none

Changes and notes

isort .
black .

Verification and Testing

Run

simulate run -v --pdb src/vivarium_sodium_reduction/model_specifications/model_spec.yaml

and confirm that it still runs to completion in the same amount of time. It ran a bit faster, but not enough faster to make me very suspicious... (197s now vs 237s before)