[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>

vllm_ascend/worker/worker_v1.py

@@ -47,7 +47,7 @@ from vllm_ascend.cpu_binding import bind_cpus
 from vllm_ascend.device_allocator.camem import CaMemAllocator
 from vllm_ascend.distributed.parallel_state import init_ascend_model_parallel
 from vllm_ascend.platform import NPUPlatform
-from vllm_ascend.utils import (init_ascend_soc_version,
+from vllm_ascend.utils import (init_ascend_soc_version, is_enable_nz,
                                prefill_context_parallel_enable,
                                register_ascend_customop, sleep_mode_enabled,
                                try_register_lib, vllm_version_is)
@@ -184,6 +184,11 @@ class NPUWorker(WorkerBase):
             raise ValueError(
                 "Sleep mode is not enabled. Please compile vllm-ascend with COMPILE_CUSTOM_KERNELS=1."
             )
+
+        if is_enable_nz():
+            raise ValueError(
+                "FRACTAL_NZ mode is enabled. This may cause model parameter precision issues "
+                "in the RL scenarios. Please set VLLM_ASCEND_ENABLE_NZ=0.")
         allocator = CaMemAllocator.get_instance()
         allocator.wake_up(tags=tags)