Fix GH Actions tests

[ethanwhite]

This fixes our failing GH Actions tests:

1. Installs required system files (something in the default build environment must have changed) (Fixes Check if version limit on setuptools can be removed from environment.yml #631)
2. Updates setup-micromamba usage, which changed upstream
3. Install pycocotools from pip since conda install is failing on Python 3.12
4. Uses separate runs for tests, style, and notebook checks so that failing tests actually result in a failed build (Fixes GH Actions build passing when tests erroring #651)
5. Fixes some yapf style issues and a missing dependency to get the test passing