[Mypy] Better fixes for the mypy issues in vllm/config (#37902)

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

tests/models/multimodal/generation/test_keye.py

@@ -1,6 +1,5 @@
 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
-from dataclasses import asdict
 from typing import NamedTuple
 
 import pytest
@@ -29,14 +28,6 @@ def test_keye_vl(image_assets, question: str):
     images = [asset.pil_image for asset in image_assets]
     image_urls = [encode_image_url(image) for image in images]
 
-    engine_args = EngineArgs(
-        model=MODEL_NAME,
-        trust_remote_code=True,
-        max_model_len=8192,
-        max_num_seqs=5,
-        limit_mm_per_prompt={"image": len(image_urls)},
-    )
-
     placeholders = [{"type": "image", "image": url} for url in image_urls]
     messages = [
         {
@@ -54,8 +45,14 @@ def test_keye_vl(image_assets, question: str):
         messages, tokenize=False, add_generation_prompt=True
     )
 
-    engine_args = asdict(engine_args) | {"seed": 42}
-    llm = LLM(**engine_args)
+    llm = LLM(
+        model=MODEL_NAME,
+        trust_remote_code=True,
+        max_model_len=8192,
+        max_num_seqs=5,
+        limit_mm_per_prompt={"image": len(image_urls)},
+        seed=42,
+    )
 
     sampling_params = SamplingParams(
         temperature=0.0, max_tokens=256, stop_token_ids=None