Use `ruff format` instead of `black`

[jherland]

Ruff comes with a built-in formatter (ruff format) which serves as a drop-in replacement for black. The difference in the formatting are minuscule, and can be seen in the second commit in this PR.

Also remove isort as a formatting dependency, since ruff check already performs the same checks.

Commits:

• Use ruff's default line-length
• Formatting changes introduced by ruff format .
• noxfile.py: Run ruff format instead of black
• Remove black as a dependency
• Remove isort as a formatting dependency
• Update docs to mention ruff instead of black + isort