Fix annotations in _autograd.pyi (#55706)
Summary:
`str` is reserved keyword, besides parameter name in `profiler_kineto.h` is `path`:
https://github.com/pytorch/pytorch/blob/6ee333cdb53d600377f6aa9992123253f2fa5132/torch/csrc/autograd/profiler_kineto.h#L209
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55706
Reviewed By: janeyx99
Differential Revision: D27686286
Pulled By: malfet
fbshipit-source-id: b27e8e3812214218054be0e69493177bb728d8d7
