Update on "Remove internal usage of all config functions like int4_weight_only"

**Summary:** These are now deprecated as of #2994. We should
stop using them internally as well.

**Test Plan:** CI

[ghstack-poisoned]

Author: andrewor14

test/quantization/test_quant_api.py

@@ -750,7 +750,6 @@ def test_int4wo_cuda_serialization(self):
             # load state_dict in cuda
             model.load_state_dict(sd, assign=True)
 
-
     def test_config_deprecation(self):
         """
         Test that old config functions like `int4_weight_only` trigger deprecation warnings.