[quant][pt2e][bc-breaking] Remove fold_quantize flag (#118701)
Summary:
This is a follow up to https://github.com/pytorch/pytorch/pull/118605 to remove `fold_quantize` flag from
`convert_pt2e`
Test Plan: CI
Differential Revision: D53247301
BC Breaking Note:
flag `fold_quantize` set to True `convert_pt2e` and now we'll fold the quantize op in the weight by default, so users will see model size reduction by default after pt2e quantization.
2.2
```
folded_model = convert_pt2e(model, fold_quantize=True)
non_folded_model = convert_pt2e(model)
```
2.3
```
folded_model = convert_pt2e(model)
non_folded_model = convert_pt2e(model, fold_quantize=False)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/118701
Approved by: https://github.com/andrewor14, https://github.com/leslie-fang-intel
