pytest rules to ban xunit-style setup

### Summary

It would be nice if Ruff had (optional) rules to ban pytest's xunit-style setup methods and encourage fixtures instead: https://docs.pytest.org/en/stable/how-to/xunit_setup.html

- setup_module
- teardown_module
- setup_class
- teardown_class
- setup_method
- teardown_method
- setup_function
- teardown_function

Start with the linked pytest xunit setup documentation and review Ruff's existing rule conventions. Define optional rules covering the eight listed setup and teardown methods, with diagnostics that encourage fixtures, then add coverage for each method and verify the rules behave as configured.

Written by the indexing model from the issue text.