### What this PR does / why we need it? As vllm will set `cudagraph_mode` to `NONE` before `check_and_update_config` in post init of `VllmConfig` (5da4f5d857/vllm/config/__init__.py (L3630)), we always have `cudagraph_mode` isn't `None`, thus we must remove this check and add it when the related adaption in vllm is done. part of https://github.com/vllm-project/vllm-ascend/pull/2577, will add the e2e test on applying reply after the CI refactor is done ### How was this patch tested? CI passed with existing test. - vLLM version: v0.10.1.1 - vLLM main:f48a9af892Signed-off-by: MengqingCao <cmq0113@163.com>