pytest-asyncio 0.23 doesn't allow class-scoped fixtures outside of class definition

[av223119]

It appears that the pytest-asyncio 0.23 broke class-scoped fixtures defined outside of the class. Namely, I used to have the following setup:

conftest.py:

@pytest_asyncio.fixture(scope="class")
async def run_important_program_in_class() -> AsyncGenerator[ImportantProgram, None]:
    """runs one Program instance per test class"""
    async with run_important_program(cfg=generate_cfg()) as p:
        yield p

and then the test classes used
@pytest.mark.usefixtures("run_important_program_in_class")

however with upgrade to 0.23, now the following error being reported:

ERROR my_example_test.py - _pytest.config.exceptions.UsageError: my_example_test.py is marked to be run i
n an event loop with scope class, but is not part of any class

The error disappears of the fixture is moved to the class definition, like this:

Class TestSomeStuff:
    @pytest_asyncio.fixture(scope="class")
    async def run_important_program_in_class() -> AsyncGenerator[ImportantProgram, None]:
        async with run_important_program(cfg=generate_cfg()) as p:
            yield p

But this approach leads to significant code duplication

[av223119]

Looks like the root cause of this is #706