revert bad json (#5370)

langchain/agents/chat/output_parser.py

@@ -1,8 +1,8 @@
+import json
 from typing import Union
 
 from langchain.agents.agent import AgentOutputParser
 from langchain.agents.chat.prompt import FORMAT_INSTRUCTIONS
-from langchain.output_parsers.json import parse_json_markdown
 from langchain.schema import AgentAction, AgentFinish, OutputParserException
 
 FINAL_ANSWER_ACTION = "Final Answer:"
@@ -18,7 +18,8 @@ class ChatOutputParser(AgentOutputParser):
                 {"output": text.split(FINAL_ANSWER_ACTION)[-1].strip()}, text
             )
         try:
-            response = parse_json_markdown(text)
+            action = text.split("```")[1]
+            response = json.loads(action.strip())
             return AgentAction(response["action"], response["action_input"], text)
 
         except Exception: