Properly capturing argument names for decorated/wrapped functions (#96557)
`inspect.getfullargspec` does not properly handle functions/methods wrapped by functools.wraps(). As a result, it gets an empty list of `args` in FullArgSpec.
This PR rewrites the logic using `inspect.signature`, which handles functools.wraps() correctly.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/96557
Approved by: https://github.com/jansel
