## Summary
Part of #8771. flake8-pyi will emit a Y018 error for unused TypeVars,
ParamSpecs or TypeVarTuples; Ruff currently only emits PYI018 for unused
TypeVars.
This is my first "proper" Ruff PR -- let me know if there's a better way
of doing this! Not sure if the repeated calls to `match_typing_expr()`
are ideal.
## Test Plan
I manually updated the fixtures to add some unused ParamSpecs and
TypeVarTuples, and then updated the snapshots using `cargo insta
review`. All tests then passed when run using `cargo test`.