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

examples/offline_inference_npu_long_seq.py

@@ -42,6 +42,7 @@ if __name__ == "__main__":
         enable_chunked_prefill=False,
         max_num_batched_tokens=2048,
         max_model_len=1024,
+        additional_config={"ascend_scheduler_config": {"enabled": False}},
         max_num_seqs=1,
         block_size=128,
         gpu_memory_utilization=0.9