fix http session closed error

[yaodongen]

[agora_yde] 2024-11-21 16:21:21,493 - openai_v2v_python - INFO - 27637 - [extension.py:380] - append item {'id': 'item_AW4DgJBUU90q5QBQaQMeQ', 'object': 'realtime.item', 'type': 'function_call', 'status': 'completed', 'name': 'bing_search', 'call_id': 'call_bvB5RUNoyydCup88', 'arguments': '{"query":"2024 美国总统选举结果"}'}
[agora_yde] 2024-11-21 16:21:21,493 - openai_v2v_python - INFO - 27637 - [extension.py:384] - remove history item_AW4COffmXDIvNH6XmI7Hz
[agora_yde] 11-21 16:21:21.510 27637(27792) W on_cmd@llm_tool.py:58 [bingsearch_tool_python] on_cmd failed: Traceback (most recent call last):
[agora_yde]   File "/app/agents/ten_packages/system/ten_ai_base/interface/ten_ai_base/llm_tool.py", line 46, in on_cmd
[agora_yde]     result = await asyncio.create_task(self.run_tool(ten_env, tool_name, tool_args))
[agora_yde]   File "/app/agents/ten_packages/extension/bingsearch_tool_python/extension.py", line 129, in run_tool
[agora_yde]     result = await self._do_search(args)
[agora_yde]   File "/app/agents/ten_packages/extension/bingsearch_tool_python/extension.py", line 141, in _do_search
[agora_yde]     results = await self._bing_search_results(query, count=self.k)
[agora_yde]   File "/app/agents/ten_packages/extension/bingsearch_tool_python/extension.py", line 160, in _bing_search_results
[agora_yde]     async with session.get(DEFAULT_BING_SEARCH_ENDPOINT, headers=headers, params=params) as response:
[agora_yde]   File "/usr/local/lib/python3.10/dist-packages/aiohttp/client.py", line 1355, in __aenter__
[agora_yde]     self._resp: _RetType = await self._coro
[agora_yde]   File "/usr/local/lib/python3.10/dist-packages/aiohttp/client.py", line 492, in _request
[agora_yde]     raise RuntimeError("Session is closed")
[agora_yde] RuntimeError: Session is closed

In local debugging, a problem was found that the session of bingsearch_tool_python expires during long conversations, so a check needs to be added to recreate it.

[cyfyifanchen]

@yaodongen thanks for the PR.