Support `typing.get_type_hints(partial(fn, ...))` by 'unwrapping' the `partial`, and discarding hints for bound arguments

We added this to Hypothesis' get_type_hints() helper a few years ago, and while most of that function is clearly not suitable to upstream, it struck me recently that "works with functools.partial" could quite reasonably be added to the stdlib function.

It's also plausible that the typing module prefers to avoid calling inspect.signature, though I don't have a great sense of how to determine which parameters have been bound without getting the signature of the partial object. In any case, the implementation need not be the same as in Hypothesis, although as the author you're welcome to use that code if you'd like.

Commencez par lire l’implémentation existante de typing.get_type_hints et l’utilitaire Hypothesis référencé dans hypothesis-python/src/hypothesis/internal/compat.py. Vérifiez comment functools.partial et inspect.signature exposent les arguments liés, puis définissez des tests montrant que les partials sont déballés et que les annotations des arguments liés sont ignorées. C’est terminé lorsque le comportement est couvert sans casser les cas existants de get_type_hints.