[Bugfix] fix sleepmode level2 e2e test (#4019)

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

enable sleepmode level2 e2e test and add the check logic to ensure the
nz is not enabled.

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

no

### How was this patch tested?

use e2e tests


- vLLM version: v0.11.0
- vLLM main:
83f478bb19

Signed-off-by: wangx700 <wangxin700@huawei.com>

tests/ut/worker/test_worker_v1.py

@@ -1,3 +1,4 @@
+import os
 import unittest
 from unittest.mock import MagicMock, patch
 
@@ -273,6 +274,7 @@ class TestNPUWorker(TestBase):
 
     @patch("vllm_ascend.worker.worker_v1.sleep_mode_enabled")
     @patch("vllm_ascend.worker.worker_v1.CaMemAllocator")
+    @patch.dict(os.environ, {"VLLM_ASCEND_ENABLE_NZ": "0"})
     def test_wake_up_mode_enabled(self, mock_allocator_class,
                                   mock_sleep_mode_enabled):
         """Test wake_up method when sleep mode is enabled"""
@@ -295,6 +297,7 @@ class TestNPUWorker(TestBase):
             mock_allocator.wake_up.assert_called_once_with(tags=["test_tag"])
 
     @patch("vllm_ascend.worker.worker_v1.sleep_mode_enabled")
+    @patch.dict(os.environ, {"VLLM_ASCEND_ENABLE_NZ": "0"})
     def test_wake_up_mode_disabled_raises_error(self, mock_sleep_mode_enabled):
         """Test wake_up method raises exception when sleep mode is disabled"""
         from vllm_ascend.worker.worker_v1 import NPUWorker