### What this PR does / why we need it?
fix bug: In the mooncake pooling scenario, when the client closes the
request, the server fails to locate the request, leading to the server
hanging.oling scenario, when the client closes the request, the server
fails to locate the request, leading to the server hanging.
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
Pull up the PD separated pooling service, send requests using aisbench,
press CTRL+C twice, and check if the vllm_ascend service exit.
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Signed-off-by: linhebiwen <linhebiwen@gmail.com>
33514a4cc2