[misc] improve cloudpickle registration and tests (#10202)

Signed-off-by: youkaichao <youkaichao@gmail.com>

vllm/engine/arg_utils.py

@@ -19,8 +19,6 @@ from vllm.logger import init_logger
 from vllm.model_executor.layers.pooler import PoolingType
 from vllm.model_executor.layers.quantization import QUANTIZATION_METHODS
 from vllm.platforms import current_platform
-from vllm.transformers_utils.config import (
-    maybe_register_config_serialize_by_value)
 from vllm.transformers_utils.utils import check_gguf_file
 from vllm.utils import FlexibleArgumentParser, StoreBoolean
 
@@ -1013,8 +1011,6 @@ class EngineArgs:
                     "supported for multimodal models and has been disabled.")
             self.enable_prefix_caching = False
 
-        maybe_register_config_serialize_by_value(self.trust_remote_code)
-
         cache_config = CacheConfig(
             # neuron needs block_size = max_model_len
             block_size=self.block_size if self.device != "neuron" else