3a6238d8c2
## Summary The next sync of typeshed would have failed without manual changes anyway, so I'm doing one manual sync + the required changes in our `sys.platform` tests (which are necessary because of my tiny typeshed PR here: https://github.com/python/typeshed/pull/13378). closes #15485 (the next run of the pipeline in two weeks should be fine as the bug has been fixed upstream)
Markdown files within the mdtest/ subdirectory are tests of type inference and type checking;
executed by the tests/mdtest.rs integration test.
See crates/red_knot_test/README.md for documentation of this test format.