Resolve `RuntimeError: Cannot install a trace function while another trace function is being installed`

在 Python 3.10 下重現 test_nonstreaming_chat_completion[False-True-False-False] 中的失敗，然後檢查 daemon Thread-6 (_flush_loop) 以及 traceback 中顯示的 tracing 設定。測試在沒有 RuntimeError 或由此產生的 pytest 無法擷取例外警告的情況下完成，即表示完成。

I keep seeing this:

__________ test_nonstreaming_chat_completion[False-True-False-False] ___________
/usr/lib/python3.10/threading.py:973: in _bootstrap
    self._bootstrap_inner()
/usr/lib/python3.10/threading.py:1011: in _bootstrap_inner
    _sys.settrace(_trace_hook)
E   RuntimeError: Cannot install a trace function while another trace function is being installed

The above exception was the direct cause of the following exception:
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/_pytest/runner.py:361: in from_call
    result: TResult | None = func()
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/_pytest/runner.py:250: in <lambda>
    lambda: runtest_hook(item=item, **kwds),
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/pluggy/_hooks.py:512: in __call__
    return self._hookexec(self.name, self._hookimpls.copy(), kwargs, firstresult)
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/pluggy/_manager.py:120: in _hookexec
    return self._inner_hookexec(hook_name, methods, kwargs, firstresult)
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/_pytest/logging.py:865: in pytest_runtest_call
    yield
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/pluggy/_callers.py:53: in run_old_style_hookwrapper
    return result.get_result()
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/pluggy/_callers.py:38: in run_old_style_hookwrapper
    res = yield
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/_pytest/capture.py:900: in pytest_runtest_call
    return (yield)
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/_pytest/skipping.py:268: in pytest_runtest_call
    return (yield)
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/_pytest/unraisableexception.py:183: in pytest_runtest_call
    collect_unraisable(item.config)
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/_pytest/unraisableexception.py:79: in collect_unraisable
    raise errors[0]
.tox/py3.10-litellm-v1.89.6/lib/python3.10/site-packages/_pytest/unraisableexception.py:67: in collect_unraisable
    warnings.warn(pytest.PytestUnraisableExceptionWarning(msg))
E   pytest.PytestUnraisableExceptionWarning: Exception ignored in thread started by: <bound method Thread._bootstrap of <Thread(Thread-6 (_flush_loop), started daemon 139619639223872)>>
E   Enable tracemalloc to get traceback where the object was allocated.
E   See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.