Fix linting and type-checker issues

src/crewai/task.py

@@ -180,7 +180,7 @@ class Task(BaseModel):
         tools: Optional[List[Any]] = None,
     ) -> Future[TaskOutput]:
         """Execute the task asynchronously."""
-        future = Future()
+        future: Future[TaskOutput] = Future()
         threading.Thread(
             target=self._execute_task_async, args=(agent, context, tools, future)
         ).start()
@@ -388,7 +388,6 @@ class Task(BaseModel):
             converter.to_pydantic() if self.output_pydantic else converter.to_json()
         )
 
-
         if isinstance(exported_result, ConverterError):
             Printer().print(
                 content=f"{exported_result.message} Using raw output instead.",