Reformatted all the code with ruff

[thomasahle]

As per our discussions, I ran ruff . --fix on the entire code base. I had to change a few things to get the tests to still run:

[tool.ruff.lint.per-file-ignores]
"**/{tests,docs}/*" = ["ALL"]
"**__init__.py" = ["F401"]

The first line just disables linting/error fixing on the tests. This was necessary, because some tests do stuff like importing List rather than using list, because it wants to be backwards compatible. The line "**__init__.py" = ["F401"] prevents ruff from removing unused imports in __init__.py files, which are used to make those modules publicly available.