Revert "drop ascend scheduler" (#4580)

Reverts vllm-project/vllm-ascend#4498
- vLLM version: v0.11.2
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.2

tests/e2e/nightly/models/test_qwen3_235b_w8a8.py

@@ -63,6 +63,11 @@ async def test_models(model: str, mode: str) -> None:
         "PYTORCH_NPU_ALLOC_CONF": "expandable_segments:True",
         "VLLM_ASCEND_ENABLE_FLASHCOMM1": "1"
     }
+    additional_config: dict[str, Any] = {
+        "ascend_scheduler_config": {
+            "enabled": False
+        },
+    }
     compilation_config = {"cudagraph_mode": "FULL_DECODE_ONLY"}
     server_args = [
         "--quantization", "ascend", "--async-scheduling",
@@ -77,6 +82,7 @@ async def test_models(model: str, mode: str) -> None:
     server_args.extend(
         ["--compilation-config",
          json.dumps(compilation_config)])
+    server_args.extend(["--additional-config", json.dumps(additional_config)])
     request_keyword_args: dict[str, Any] = {
         **api_keyword_args,
     }