fix: allow load_gen_results to load error

Author: EYH0602

src/tfbench/load.py

@@ -35,5 +35,5 @@ def load_tfb_from_hf(split: str = "base") -> list[BenchmarkTask]:
 
 def load_gen_results_jsonl(result_file: str) -> list[LMAnswer | None]:
     """load generation results from a jsonl file"""
-    objs: list[dict[str, str | None]] = orjsonl.load(result_file)  # type: ignore
-    return [from_dict(LMAnswer, obj) for obj in objs]
+    objs: list[dict[str, str]] = orjsonl.load(result_file)  # type: ignore
+    return [from_dict(LMAnswer, obj) if "answer" in obj else None for obj in objs]