Update src/tfbench/lm/_hf.py

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: EYH0602

src/tfbench/lm/_hf.py

@@ -49,8 +49,5 @@ def _gen(self, prompt: str) -> LMAnswer:
         output_ids = generated_ids[0][len(model_inputs.input_ids[0]) :].tolist()
         output = self.tokenizer.decode(output_ids, skip_special_tokens=True).strip("\n")
 
-        if output is None:
-            raise NoneResponseError(self.model_name)
-
         content, thinking_content = extract_thinking_content(output)
         return LMAnswer(answer=content, reasoning_steps=thinking_content)