Expand Semantic Syntax Coverage (#17725)
Re: #17526
## Summary
Adds tests to red knot and `linter.rs` for the semantic syntax.
Specifically add tests for `ReboundComprehensionVariable`,
`DuplicateTypeParameter`, and `MultipleCaseAssignment`.
Refactor the `test_async_comprehension_in_sync_comprehension` →
`test_semantic_error` to be more general for all semantic syntax test
cases.
## Test Plan
This is a test.
## Question
I'm happy to contribute more tests the coming days.
Should that happen here or should we merge this PR such that the
refactor `test_async_comprehension_in_sync_comprehension` →
`test_semantic_error` is available on main and others can chime in, too?
