Fix of DeepSeek Error in KV Pool Mixed Deployment Scenario (#3087)

### What this PR does / why we need it?
A new kv_role "kv_both" is added to run mixed deployment scenarios. The
mixed deployment will involve a decode phase, where with_prefill should
be false.

### Does this PR introduce _any_ user-facing change?

### How was this patch tested?

- vLLM version: v0.10.2
- vLLM main:
c60e6137f0

Signed-off-by: fems14 <1804143737@qq.com>

vllm_ascend/worker/model_runner_v1.py

@@ -2406,7 +2406,7 @@ class NPUModelRunner(LoRAModelRunnerMixin):
                                         dtype=np.int32)
 
         # Force dummy run on prefill stage when this node is deemed as kv producer.
-        if self.is_kv_producer:
+        if self.is_kv_producer and not self.is_kv_consumer:
             with_prefill = True
 
         attn_metadata = self._build_attention_metadata(