### What this PR does / why we need it?
To fix ops test, where `model_config` has been set to `None` and doesn't
has `hf_config` attribute, we have added a check for `model_config` to
guarantee it is not `None_Type`.
- vLLM main:
2918c1b49c
Signed-off-by: shen-shanshan <467638484@qq.com>