Backport PR #42413: CI: runtime warning in npdev build (#42415)

Co-authored-by: jbrockmendel <[email protected]>

Author: meeseeksmachine

pandas/tests/scalar/timedelta/test_arithmetic.py

@@ -18,7 +18,6 @@
     NaT,
     Timedelta,
     Timestamp,
-    compat,
     offsets,
 )
 import pandas._testing as tm
@@ -438,7 +437,7 @@ def test_td_div_numeric_scalar(self):
                 np.float64("NaN"),
                 marks=pytest.mark.xfail(
                     # Works on numpy dev only in python 3.9
-                    is_numpy_dev and not compat.PY39,
+                    is_numpy_dev,
                     raises=RuntimeWarning,
                     reason="https://github.com/pandas-dev/pandas/issues/31992",
                 ),