Enable more Ruff lints & fix issues (#2419)
* Remove antiquated flake8 and isort configuration
* Bump to Ruff 0.2.1
* Explain ruff options
* Autofix Ruff B010 (static `setattr`)
* Autofix Ruff B009 (static `getattr`)
* Enable Ruff UP (not UP007); auto-fix
* Fix remaining Ruff UP complaints
* Fix a couple more format calls
