[main][BugFix] Fixed an accuracy bug of Qwen3-next-MTP when batched inferring (#4932)

### What this PR does / why we need it?
Fixes an accuracy bug of Qwen3-next-MTP when batched inferring.
It is descibed in
https://github.com/vllm-project/vllm-ascend/issues/4930.

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

Signed-off-by: drslark <slarksblood@qq.com>

tests/e2e/multicard/test_qwen3_next.py

@@ -61,9 +61,14 @@ def test_qwen3_next_distributed_mp_full_decode_only_tp4():
         del vllm_model
 
 
-# TODO: Fix the accuary of batch chunked prefill
 def test_qwen3_next_distributed_mp_eager_mtp_similarity_tp4():
-    example_prompts = ["Hello, my name is"]
+    example_prompts = [
+        "Hello, my name is",
+        "The president of the United States is",
+        "The capital of France is",
+        "The future of AI is",
+    ]
+
     max_tokens = 20
 
     with VllmRunner(