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.

Comece lendo a implementação existente de typing.get_type_hints e o helper referenciado do Hypothesis em hypothesis-python/src/hypothesis/internal/compat.py. Verifique como functools.partial e inspect.signature expõem argumentos vinculados e, em seguida, defina testes mostrando que os partials são desembrulhados e que as dicas de tipo dos argumentos vinculados são descartadas. Está concluído quando o comportamento estiver coberto sem quebrar os casos existentes de get_type_hints.