Revert "[export] Allow optional call-spec (#105041)"
This reverts commit 194fe1d12f9860734cc28ed21bdabda2fbb06336.
Reverted https://github.com/pytorch/pytorch/pull/105041 on behalf of https://github.com/atalman due to broke lintrunner ([comment](https://github.com/pytorch/pytorch/pull/105041#issuecomment-1634911637))
