Revert "[quant][pt2e] store scale/zero_point as tensor attributes to support serialization (#105894)"
This reverts commit 3ca71ed735257cb7ad377b57a45057c265893a40.
Reverted https://github.com/pytorch/pytorch/pull/105894 on behalf of https://github.com/huydhn due to breaking executorch tests internally ([comment](https://github.com/pytorch/pytorch/pull/105894#issuecomment-1654831950))
