[quant][fx] Remove "additional_fusion_pattern" from prepare_custom_config_dict (#75377)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/75377
This is in `prepare_custom_config_dict` but we never talked about them before, and we didn't find use cases internally
So it should be OK to remove.
We can now serve the same use case with `backend_config_dict` api
Test Plan:
python test/test_quantization.py TestQuantizeFx
python test/test_quantization.py TestQuantizeFxOps
Imported from OSS
Reviewed By: vkuzo
Differential Revision: D35451961
fbshipit-source-id: 8a44c4518eecd50fab7ea2ff06697527b1cdb049
(cherry picked from commit 964183ed26bd8f367a4cf7fcc991eb519dc31a58)
