Add property test generators for the new variable-length tuples. This covers homogeneous tuples as well. The property tests did their job! This identified several fixes we needed to make to various type property methods. cf https://github.com/astral-sh/ruff/pull/18600#issuecomment-2993764471 --------- Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Markdown files within the mdtest/ subdirectory are tests of type inference and type checking;
executed by the tests/mdtest.rs integration test.
See crates/ty_test/README.md for documentation of this test format.