refactor: improve parsing logic in structured output parser

- Updated the logic for handling lists in the parsing process to ensure only dictionary items are considered, enhancing robustness.
- Maintained existing functionality while improving the clarity and reliability of the output parsing.

api/core/llm_generator/output_parser/structured_output.py

@@ -250,7 +250,7 @@ def _parse_structured_output(result_text: str) -> Mapping[str, Any]:
         if not isinstance(temp_parsed, dict):
             # handle reasoning model like deepseek-r1 got '<think>\n\n</think>\n' prefix
             if isinstance(temp_parsed, list):
-                temp_parsed = next((item for item in parsed if isinstance(item, dict)), {})
+                temp_parsed = next((item for item in temp_parsed if isinstance(item, dict)), {})
             else:
                 raise OutputParserError(f"Failed to parse structured output: {result_text}")
         structured_output = cast(dict, temp_parsed)