### What this PR does / why we need it? On Arm systems, os.sched_yield() does not take effect, causing the GIL (Global Interpreter Lock) to remain unrelinquished and resulting in CPU bound issues. This PR applies a patch to sched_yield in vLLM, making the process execute time.sleep(0) instead to release the GIL. ### Does this PR introduce _any_ user-facing change? Signed-off-by: fems14 <1804143737@qq.com> Co-authored-by: fems14 <74094523+fems14@users.noreply.github.com>