Fix type checking errors in torch/ao/quantization/quantize_fx.py (#66804)
Summary:
- [x] Fix the Pyre type checking errors in `torch/ao/quantization/quantize_fx.py`
```
torch/quantization/quantize_fx.py:41:8 Incompatible variable type [9]: fuse_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:143:16 Incompatible variable type [9]: prepare_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:144:16 Incompatible variable type [9]: equalization_qconfig_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:206:8 Incompatible variable type [9]: prepare_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:230:12 Incompatible variable type [9]: fuse_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:268:8 Incompatible variable type [9]: prepare_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:269:8 Incompatible variable type [9]: equalization_qconfig_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:427:8 Incompatible variable type [9]: prepare_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:464:8 Incompatible variable type [9]: convert_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:486:8 Incompatible variable type [9]: convert_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
torch/quantization/quantize_fx.py:547:8 Incompatible variable type [9]: convert_custom_config_dict is declared to have type `Dict[str, typing.Any]` but is used as type `None`.
```
Fixes the issue: [MLH-Fellowship/pyre-check/issues/76](https://github.com/MLH-Fellowship/pyre-check/issues/76)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/66804
Reviewed By: onionymous
Differential Revision: D31738171
Pulled By: 0xedward
fbshipit-source-id: 00d4c5749c469aff39a1531365461ced747e52fc