Skip the complex test on external scheduler, as it causes a flaky test on GitHub

Author: nils-braun

tests/integration/test_complex.py

@@ -1,6 +1,9 @@
 from dask.datasets import timeseries
 
+from tests.integration.fixtures import skip_if_external_scheduler
 
+
+@skip_if_external_scheduler
 def test_complex_query(c):
     df = timeseries(freq="1d").persist()
     c.create_table("timeseries", df)