Compatibility with pytest 8

[hrnciar]

I am getting a test failure when built with pytest 8.2.1.

=================================== FAILURES ===================================
_______________ TestAsyncCaseWithCustomLoop.test_await_async_add _______________
../../BUILDROOT/python-aiounittest-1.3.1-16.fc41.x86_64/usr/lib/python3.12/site-packages/aiounittest/helpers.py:137: in wrapper
    future = asyncio.ensure_future(ret, loop=loop)
/usr/lib64/python3.12/asyncio/tasks.py:695: in ensure_future
    return loop.create_task(coro_or_future)
/usr/lib64/python3.12/asyncio/base_events.py:456: in create_task
    self._check_closed()
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <_UnixSelectorEventLoop running=False closed=True debug=False>

    def _check_closed(self):
        if self._closed:
>           raise RuntimeError('Event loop is closed')
E           RuntimeError: Event loop is closed

/usr/lib64/python3.12/asyncio/base_events.py:541: RuntimeError
=============================== warnings summary ===============================
tests/test_asynctestcase_get_event_loop.py:30
  /builddir/build/BUILD/aiounittest-1.3.1/tests/test_asynctestcase_get_event_loop.py:30: DeprecationWarning: There is no current event loop
    self.my_loop = asyncio.get_event_loop()

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=========================== short test summary info ============================
FAILED tests/test_asynctestcase_get_event_loop.py::TestAsyncCaseWithCustomLoop::test_await_async_add
============== 1 failed, 8 passed, 2 xfailed, 1 warning in 0.89s ===============