Enable Ruff RUF006; Hard reference to asyncio.create_task return value (#88216)

* Enable Ruff RUF006

* Fix test

---------

Co-authored-by: Paulus Schoutsen <balloob@gmail.com>

pyproject.toml

@@ -258,6 +258,7 @@ select = [
     "SIM401", # Use get from dict with default instead of an if block
     "T20",  # flake8-print
     "TRY004", # Prefer TypeError exception for invalid type
+    "RUF006", # Store a reference to the return value of asyncio.create_task
     "UP",  # pyupgrade
     "W",  # pycodestyle
 ]

tests/test_runner.py

@@ -122,18 +122,21 @@ def test_run_does_not_block_forever_with_shielded_task(hass, tmpdir, caplog):
 async def test_unhandled_exception_traceback(hass, caplog):
     """Test an unhandled exception gets a traceback in debug mode."""
 
+    raised = asyncio.Event()
+
     async def _unhandled_exception():
+        raised.set()
         raise Exception("This is unhandled")
 
     try:
         hass.loop.set_debug(True)
-        asyncio.create_task(_unhandled_exception())
+        task = asyncio.create_task(_unhandled_exception())
+        await raised.wait()
+        # Delete it without checking result to trigger unhandled exception
+        del task
     finally:
         hass.loop.set_debug(False)
 
-    await asyncio.sleep(0)
-    await asyncio.sleep(0)
-
     assert "Task exception was never retrieved" in caplog.text
     assert "This is unhandled" in caplog.text
     assert "_unhandled_exception" in caplog.text