test_owdbscan: Remove test for get_kth_distances with orange distances

This is never used except in tests and raises deprecation warnings with
numpy 1.25. This in turn results in significant test runtime of 40+
seconds for this test.

Orange/widgets/unsupervised/tests/test_owdbscan.py

@@ -173,12 +173,6 @@ def test_get_kth_distances(self):
         # dists must be sorted
         np.testing.assert_array_equal(dists, np.sort(dists)[::-1])
 
-        # test with different distance - e.g. Orange distance
-        dists = get_kth_distances(self.iris, Euclidean, k=5)
-        self.assertEqual(len(self.iris), len(dists))
-        # dists must be sorted
-        np.testing.assert_array_equal(dists, np.sort(dists)[::-1])
-
     def test_metric_changed(self):
         w = self.widget