Revert "faketensor: prevent deepcopy from cloning FakeTensorMode (#104476)"
This reverts commit c54afea6eeb016b0a5ad7006f25746b2c83eaf9a.
Reverted https://github.com/pytorch/pytorch/pull/104476 on behalf of https://github.com/jeanschmidt due to sadly it is breaking internal tests, and I can't coordinate a FF due to timezone differences ([comment](https://github.com/pytorch/pytorch/pull/104476#issuecomment-1661808343))
