Replace flake8 and isort with ruff

[cclauss]

Ruff supports over 500 lint rules and can be used to replace Flake8 (plus dozens of plugins), isort, pydocstyle, yesqa, eradicate, pyupgrade, and autoflake, all while executing (in Rust) tens or hundreds of times faster than any individual tool.

The ruff Action uses minimal steps to run in ~5 seconds, rapidly providing intuitive GitHub Annotations to contributors.

Running the complete test matrix on GitHub Actions takes a lot of time and CPU. Given that the ruff linting job is so fast (~5 seconds) let's ensure that linting passes before the complete test matrix is run. This will cost a few seconds on each run but could save a lot of time and contention for PRs that should be cleaned up before they are fully tested.

https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idneeds

[acdha]

Looks like we need codespell to ignore the .git directory

[acdha]

Thanks for doing this! I think we get the last couple spellcheck items in & then do a second PR where we enable the pyupgrade fixes and remove the remaining Python 2 compatibility code.