[CI][BugFix] Import error fix. (#6293)

### What this PR does / why we need it?
Fix the **import error** of qwen3-next nightly test.
### Does this PR introduce _any_ user-facing change?
N/A
### How was this patch tested?

- vLLM version: v0.14.1
- vLLM main:
dc917cceb8

Signed-off-by: InSec <1790766300@qq.com>

tests/e2e/nightly/single_node/models/test_qwen3_next.py

@@ -4,7 +4,7 @@ from typing import Any
 
 import openai
 import pytest
-from vllm.utils import get_open_port
+from vllm.utils.network_utils import get_open_port
 
 from tests.e2e.conftest import RemoteOpenAIServer
 from tools.aisbench import run_aisbench_cases