Revert "Add initial support for FP8 ONNX export (#106379)"
This reverts commit 08704f96f08da5a52f65a7c3001d6ce4aae0102e.
Reverted https://github.com/pytorch/pytorch/pull/106379 on behalf of https://github.com/kit1980 due to breaking multiple internal builds ([comment](https://github.com/pytorch/pytorch/pull/106379#issuecomment-1675192700))
