refactor: Remove unused stream_task method from LangGraphAgentAdapter

- Deleted the `stream_task` method from LangGraphAgentAdapter to streamline the code and eliminate unnecessary complexity.
- This change enhances maintainability by focusing on essential functionalities within the agent adapter.

src/crewai/agents/agent_adapters/langgraph/langgraph_adapter.py

@@ -198,71 +198,6 @@ class LangGraphAgentAdapter(BaseAgentAdapter):
             )
             raise
 
-    async def stream_task(
-        self,
-        task: Any,
-        context: Optional[str] = None,
-        tools: Optional[List[BaseTool]] = None,
-    ) -> AsyncIterable[Dict[str, Any]]:
-        """Stream the execution of a task."""
-        self.create_agent_executor(tools)
-
-        try:
-            task_prompt = task.prompt() if hasattr(task, "prompt") else str(task)
-
-            if context:
-                task_prompt = self.i18n.slice("task_with_context").format(
-                    task=task_prompt, context=context
-                )
-
-            # Set up a session ID for this task
-            session_id = f"task_{id(task)}"
-
-            # Configure the invocation
-            config = {"configurable": {"thread_id": session_id}}
-
-            # Stream the execution
-            inputs = {"messages": [("user", task_prompt)]}
-
-            for item in self._graph.stream(inputs, config, stream_mode="values"):
-                message = item.get("messages", [])[-1] if "messages" in item else None
-
-                if (
-                    message is not None
-                    and hasattr(message, "tool_calls")
-                    and getattr(message, "tool_calls", None)
-                ):
-                    tool_calls = getattr(message, "tool_calls", [])
-                    if tool_calls and len(tool_calls) > 0:
-                        yield {
-                            "is_task_complete": False,
-                            "require_user_input": False,
-                            "content": f"Using tool: {tool_calls[0].name}",
-                        }
-                elif isinstance(message, ToolMessage):
-                    content = getattr(message, "content", "Tool execution complete")
-                    yield {
-                        "is_task_complete": False,
-                        "require_user_input": False,
-                        "content": f"Tool result: {content[:50]}...",
-                    }
-                elif message is not None:
-                    # Final response or intermediary thinking
-                    content = getattr(message, "content", str(message))
-                    yield {
-                        "is_task_complete": True,
-                        "require_user_input": False,
-                        "content": content,
-                    }
-
-        except Exception as e:
-            self._logger.log("error", f"Error streaming LangGraph task: {str(e)}")
-            yield {
-                "is_task_complete": True,
-                "require_user_input": False,
-                "content": f"Error: {str(e)}",
-            }
-
     def create_agent_executor(self, tools: Optional[List[BaseTool]] = None) -> None:
         """Configure the LangGraph agent for execution."""
         self.configure_tools(tools)