[quant][graphmode][fx] Remove fbgemm_backend_config_dict for now (#67066)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67066
We'll add it later when the api is ready
Test Plan: Imported from OSS
Reviewed By: vkuzo
Differential Revision: D31849079
fbshipit-source-id: 0c00d08510166b2d897cf1562c7276527319b05c
