Revert "deprecating nvfuser c++ API (#110318)"
This reverts commit bf0866fc164b1eab10a5174a57e21eb3321bef89.
Reverted https://github.com/pytorch/pytorch/pull/110318 on behalf of https://github.com/davidberard98 due to too many warnings being thrown in torchvision https://github.com/pytorch/pytorch/issues/110857 ([comment](https://github.com/pytorch/pytorch/pull/110318#issuecomment-1753245449))
