TST/CI: xfail test_scikit_learn (pandas-dev#30313)

Author: TomAugspurger

pandas/tests/test_downstream.py

@@ -67,6 +67,9 @@ def test_statsmodels():
 
 # Cython import warning
 @pytest.mark.filterwarnings("ignore:can't:ImportWarning")
+@pytest.mark.xfail(
+    reason="https://github.com/pandas-dev/pandas/issues/30309", strict=False
+)
 def test_scikit_learn(df):
 
     sklearn = import_module("sklearn")  # noqa