[Core] Remove forced None assignment for deprecated PassConfig flags (#29994)

Signed-off-by: arpitkh101 <arpit5khandelwal@gmail.com>
Co-authored-by: Cyrus Leung <tlleungac@connect.ust.hk>

vllm/config/compilation.py

@@ -4,7 +4,7 @@
 import enum
 from collections import Counter
 from collections.abc import Callable
-from dataclasses import asdict, field
+from dataclasses import field
 from pathlib import Path
 from typing import TYPE_CHECKING, Any, ClassVar, Literal
 
@@ -13,7 +13,7 @@ from pydantic.dataclasses import dataclass
 
 import vllm.envs as envs
 from vllm.compilation.inductor_pass import CallableInductorPass, InductorPass
-from vllm.config.utils import config, handle_deprecated
+from vllm.config.utils import config, get_hash_factors, handle_deprecated, hash_factors
 from vllm.logger import init_logger
 from vllm.platforms import current_platform
 from vllm.utils.import_utils import resolve_obj_by_qualname
@@ -196,7 +196,16 @@ class PassConfig:
         Any new fields that affect compilation should be added to the hash.
         Any future fields that don't affect compilation should be excluded.
         """
-        return InductorPass.hash_dict(asdict(self))
+
+        ignored_fields = [
+            "enable_fusion",
+            "enable_attn_fusion",
+            "enable_noop",
+            "enable_sequence_parallelism",
+            "enable_async_tp",
+            "enable_fi_allreduce_fusion",
+        ]
+        return hash_factors(get_hash_factors(self, ignored_factors=ignored_fields))
 
     @field_validator(
         "fuse_norm_quant",
@@ -267,14 +276,6 @@ class PassConfig:
             "v0.13.0 or v1.0.0, whichever is sooner",
         )
 
-        # Force old flags to None to ensure they are not used
-        self.enable_fusion = None
-        self.enable_attn_fusion = None
-        self.enable_noop = None
-        self.enable_sequence_parallelism = None
-        self.enable_async_tp = None
-        self.enable_fi_allreduce_fusion = None
-
         if not self.eliminate_noops:
             if self.fuse_norm_quant or self.fuse_act_quant:
                 logger.warning_once(