Refactor tests to reduce creation of venvs for speed#294

nathanjmcdougall merged 8 commits intomainusethis-python/usethis-python:mainfrom

284-only-install-pre-commit-hooks-in-one-testusethis-python/usethis-python:284-only-install-pre-commit-hooks-in-one-testCopy head branch name to clipboard