(... and I had the window open for too long and didn't notice Ken's reply before mine ^^')

@kj: thanks for the workaround! it's good to be able to change our code and not have to depend on a yet-to-be-released patch on each python version :)

That said, typing.get_type_hints() only returns the type hint, whereas our current test checks for other things (like the default value) which need to match (I think) for cython's use of `__signature__`? (I inherited all this code, so I'm not familiar with it and its history, and I'm beginning to question this test's necessity.)