Port recent change to LLMAssistantContextAggregator to universal LLMAssistantAggregator

src/pipecat/processors/aggregators/llm_response_universal.py

@@ -788,10 +788,6 @@ class LLMAssistantAggregator(LLMContextAggregator):
 
     def _context_updated_task_finished(self, task: asyncio.Task):
         self._context_updated_tasks.discard(task)
-        # The task is finished so this should exit immediately. We need to do
-        # this because otherwise the task manager would report a dangling task
-        # if we don't remove it.
-        asyncio.run_coroutine_threadsafe(self.wait_for_task(task), self.get_event_loop())
 
 
 class LLMContextAggregatorPair: