Fix MPZCH model publish

Summary: Remove _hash_zch_bucket in the inference module for model publish

Differential Revision: D84944806

Author: chaodengusc

torchrec/modules/hash_mc_modules.py

@@ -405,6 +405,8 @@ def _load_state_dict_pre_hook(
                 return
             if "_hash_zch_metadata" in state_dict:
                 del state_dict["_hash_zch_metadata"]
+            if "_hash_zch_bucket" in state_dict:
+                del state_dict["_hash_zch_bucket"]
 
         self._register_load_state_dict_pre_hook(
             _load_state_dict_pre_hook, with_module=True