Revert "[export] Lift constant tensors as buffers (#108592)" (#108893)
This reverts commit e3407238f6be0583fe6dac7e2c4897f6c4480ed4.
I gave up trying to revert the original PR in the usual way https://github.com/pytorch/pytorch/pull/108592#issuecomment-1712135536, so let's manually revert it then.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/108893
Approved by: https://github.com/izaitsevfb, https://github.com/atalman
