Update WeightTransferConfig to be more standard like the others (#33989)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

vllm/config/weight_transfer.py

@@ -1,13 +1,11 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
-from dataclasses import dataclass
 from typing import Literal
 
 from vllm.config.utils import config
 
 
 @config
-@dataclass
 class WeightTransferConfig:
     """Configuration for weight transfer during RL training."""