tests: Don't use deprecated asyncio method

It was removed in python3.14

Signed-off-by: Manuel Traut <manut@mecka.net>

Author: manut

tests/__init__.py

@@ -10,5 +10,10 @@ def tearDown(self) -> None:
         inject.clear()
 
     def run_async(self, awaitable: t.Awaitable):  # noqa: ANN201
-        loop = asyncio.get_event_loop()
-        return loop.run_until_complete(awaitable)
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+        try:
+            ret = loop.run_until_complete(awaitable)
+        finally:
+            loop.close()
+        return ret