### What this PR does / why we need it? Remove `spec_decode.metrics` patch as this has been resolved in https://github.com/vllm-project/vllm/pull/16983 (include in vllm `v0.9.0`). Returns a CUDA event recording when the copy is complete **--after modified-->** Returns a device event (NPU Event for vllm-ascend) recording when the copy is complete. Signed-off-by: shen-shanshan <467638484@qq.com>