fix: silicon change its model fix #11844 (#11847)

Signed-off-by: yihong0618 <zouzou0208@gmail.com>

api/core/model_runtime/model_providers/siliconflow/siliconflow.py

         try:
             model_instance = self.get_model_instance(ModelType.LLM)
 
-            model_instance.validate_credentials(model="deepseek-ai/DeepSeek-V2-Chat", credentials=credentials)
+            model_instance.validate_credentials(model="deepseek-ai/DeepSeek-V2.5", credentials=credentials)
         except CredentialsValidateFailedError as ex:
             raise ex
         except Exception as ex: