fix ruff linting errors 🏅

[janfb]

In #955 we introduced ruff for formatting and linting (replacing black, isort, flake8 etc).

In the pre-commit hook, ruff lint . is currently commented out because it causes hundreds of errors / violations of the linting rules.

The PR fixing this issue would run ruff lint . locally and fix all of these errors, ideally in separate commits for each type of problems. The most prominent problems are

• E501 Line too long (>88)
• B008 Do not perform function in argument defaults
• B006 Do not use mutable data structures for argument defaults
• UP006, UP007 wrong type annotations, e.g., Tuple instead of tuple.

Most of them are easy to fix because ruff gives explicit hints.

This is an annoying thing to fix. The contributor fixing this will be honored publicly 🏅