### What this PR does / why we need it?
[Feat]support dynamic quantization in allgather
### Does this PR introduce _any_ user-facing change?
### How was this patch tested?
- vLLM version: main
- vLLM main:
5931b7e5d9
Signed-off-by: withHades <244036962@qq.com>
Signed-off-by: WithHades <244036962@qq.com>