Loop factory parametrization tears down async fixtures used by sync tests

[tjkuson]

I encountered an issue with defining pytest_asyncio_loop_factories in test suites where non-async tests use async fixtures in shared loop scopes.

To reproduce:

# conftest.py

import asyncio
from collections.abc import Mapping, Callable

import pytest


def pytest_asyncio_loop_factories(
    config: pytest.Config,
    item: pytest.Item,
) -> Mapping[str, Callable[[], asyncio.AbstractEventLoop]]:
    return {"default": asyncio.new_event_loop}

# test_mre.py

from collections.abc import AsyncGenerator

import pytest
import pytest_asyncio


@pytest_asyncio.fixture(scope="session")
async def parent() -> AsyncGenerator[str]:
    yield "parent"


@pytest_asyncio.fixture(scope="session")
async def child(parent: str) -> AsyncGenerator[str]:
    yield "child"


@pytest.mark.asyncio(loop_scope="session")
async def test_async(parent) -> None:
    assert parent == "parent"


def test_sync(child: str) -> None:
    assert child == "child"

Running test_mre.py on the above using pytest-asyncio 1.4.0 and pytest 9.1.1 shows one pass and one failure with the following errror:

AssertionError: The fixture value for "parent" is not available.  This can happen when the fixture has already been torn down.

If pytest_asyncio_loop_factories is not defined in the conftest file, both tests pass.

If test_async is after test_sync, both tests pass.

The expected behaviour is that both tests pass regardless of order and pytest_asyncio_loop_factories hook implementation.

I think the fix would involve handling the loop factory for any test item that uses a pytest-asyncio-managed async fixture, not just async tests themselves.