### What this PR does / why we need it?
When kv caches are evicted from the key-value pool, it's possible that
the kv cache for pp0 is still active, but the kv cache for pp1 has
already been evicted. Therefore, a unified check is needed during the
get operation.
- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c
Signed-off-by: baxingpiaochong <771405853@qq.com>
Co-authored-by: Jade Zheng <zheng.shoujian@outlook.com>
95e6400128