initialize judge_model

main.py

@@ -69,7 +69,7 @@ if __name__ == "__main__":
         case "openai":
             logger.info(f"Using {options.openai_model} as the evolution engine")
 
-    judge_model: LLMModel | None
+    judge_model: LLMModel | None = None
     if options.judge_engine is not None:
         judge_model = LLMModel.get_model(options.judge_engine, options=options)
         logger.info(f"Using {options.judge_engine} as the judge engine")