### What this PR does / why we need it?
In the training-inference switching scenario, there is no need to resume
the model weights during KV cache resumption, as this would lead to
format mismatch.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
- vLLM version: v0.13.0
- vLLM main:
7157596103
Signed-off-by: p00465316 <panchao13@huawei.com>
Co-authored-by: p00465316 <panchao13@huawei.com>