Replace isort with ruff check "I" rule

[mwtoews]

This replaces isort with ruff check's "I" rule.

Also, small nits:

• Remove tool.ruff.target-version since it is recommended to use project.requires-python instead, which is already defined
• Expand tool.ruff.lint.select with inline comments to describe each rule selected

[JamesParrott]

This is helpful for running the checks individually without pre-commit integrated into Git. Thanks Mike