Launch actions sychronously

There's no need to run asychronously and manually send a shutdown signal.

Signed-off-by: Jacob Perron <jacob@openrobotics.org>

test_launch_ros/test/test_launch_ros/actions/test_load_composable_nodes.py

@@ -82,18 +82,11 @@ def shutdown(self):
         self._thread.join()
 
 
-def _assert_launch_no_errors(actions, *, timeout_sec=1):
+def _assert_launch_no_errors(actions):
     ld = LaunchDescription(actions)
     ls = LaunchService(debug=True)
     ls.include_launch_description(ld)
-
-    loop = osrf_pycommon.process_utils.get_loop()
-    launch_task = loop.create_task(ls.run_async())
-    loop.run_until_complete(asyncio.sleep(timeout_sec))
-    if not launch_task.done():
-        loop.create_task(ls.shutdown())
-        loop.run_until_complete(launch_task)
-    assert 0 == launch_task.result()
+    assert 0 == ls.run()
     return ls.context