Async tests no longer work on python 3.11

[soldag]

Async test functions aren't awaited on python 3.11 when annotated with a DDT decorator. Consequently, such tests will always pass. This can be reproduced with the following minimal example:

import asyncio
from unittest import IsolatedAsyncioTestCase

from ddt import ddt, data


@ddt
class TestDdt(IsolatedAsyncioTestCase):
    @data(1)
    async def test_ddt(self, value: int) -> None:
        await asyncio.sleep(1)
        self.assertNotEqual(value, 1)

Executing this test case results in the following warnings:

==================================================================== test session starts =====================================================================
platform linux -- Python 3.11.5, pytest-7.4.2, pluggy-1.3.0
rootdir: /home/soldag/ddt-test
collected 1 item                                                                                                                                             

test_ddt.py .                                                                                                                                          [100%]

====================================================================== warnings summary ======================================================================
test_ddt.py::TestDdt::test_ddt_1_1
  /usr/lib/python3.11/unittest/async_case.py:90: RuntimeWarning: coroutine 'TestDdt.test_ddt' was never awaited
    if self._callMaybeAsync(method) is not None:
  Enable tracemalloc to get traceback where the object was allocated.
  See https://docs.pytest.org/en/stable/how-to/capture-warnings.html#resource-warnings for more info.

test_ddt.py::TestDdt::test_ddt_1_1
  /usr/lib/python3.11/unittest/case.py:678: DeprecationWarning: It is deprecated to return a value that is not None from a test case (<bound method TestDdt.test_ddt of <test_ddt.TestDdt testMethod=test_ddt_1_1>>)
    return self.run(*args, **kwds)

-- Docs: https://docs.pytest.org/en/stable/how-to/capture-warnings.html
=============================================================== 1 passed, 2 warnings in 0.05s ================================================================