fix profile run for vl model (#5136)

### What this PR does / why we need it?

### Does this PR introduce _any_ user-facing change?

### How was this patch tested?

- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

---------

Signed-off-by: 李少鹏 <lishaopeng21@huawei.com>

tests/e2e/singlecard/test_vlm.py

@@ -39,7 +39,6 @@ def test_multimodal_vl(prompt_template):
     images = [image] * len(img_questions)
     prompts = prompt_template(img_questions)
     with VllmRunner("Qwen/Qwen3-VL-8B-Instruct",
-                    max_model_len=4096,
                     mm_processor_kwargs={
                         "min_pixels": 28 * 28,
                         "max_pixels": 1280 * 28 * 28,