replace black with `ruff format` a Python string using `subprocess`

[Josverl]

For what it's worth; here's an example of how you could ruff format a Python string using subprocess: https://gist.github.com/jorenham/63942278b01515ffdeb0c7d4d1895684

Originally posted by @jorenham in https://github.com/astral-sh/ruff/issues/659#issuecomment-2895157896