Support a method of copying function signature

Feature
Capability to copy a functions signature, related to typing.ParamSpec.

def foo(a: str) -> None:
    ...


# pseudo code
def bar(*args: foo.args, **kwargs: foo.kwargs) -> foo.return_type:
    return foo(*args, **kwargs)

Pitch
If I want to forward a call to another method in a type safe way it requires duplicating type definitions which can rapidly become unwieldy and error prone(especially if the function is in a third party module). I would love a way to just say that one functions signature is the same as another functions signature (with support for typing.Concatenate)

Maybe

extend functionality of ParamSpec to be generic to a Callable?

def bar(*args: ParamSpec[foo].args, **kwargs: ParamSpec[foo].kwargs) -> None:
    return foo(*args, **kwargs)

• basedmypy https://github.com/KotlinIsland/basedmypy/issues/257

Start by reading the issue's examples and the discussion of typing.ParamSpec and typing.Concatenate. Review the related basedmypy issue for context. Done would mean defining and implementing an agreed mechanism for forwarding a function signature, including the behavior for arguments, keyword arguments, return types, and Concatenate.