🔧 chore(chat.py): reset chat history when building a flow to ensure a clean state

The chat history is now reset when building a flow to ensure that the chat starts with a clean state. This helps prevent any potential issues or conflicts that may arise from previous chat interactions.

src/backend/langflow/api/v1/chat.py

@@ -128,6 +128,8 @@ async def stream_build(flow_id: str):
                 yield str(StreamData(event="message", data=input_keys_response))
 
             chat_manager.set_cache(flow_id, langchain_object)
+            # We need to reset the chat history
+            chat_manager.chat_history.empty_history(flow_id)
         except Exception as exc:
             logger.error("Error while building the flow: %s", exc)
             yield str(StreamData(event="error", data={"error": str(exc)}))