Tests: Small fix for cloud behavior (bigquery)

Author: erezsh

tests/test_joindiff.py

@@ -224,13 +224,15 @@ def test_diff_sorted_by_key(self):
         )
 
         diff = list(self.differ.diff_tables(self.table, self.table2))
-        expected = [
+        expected = {
             ("-", ("2", time2 + ".000000")),
             ("+", ("2", time + ".000000")),
             ("-", ("4", time2 + ".000000")),
             ("+", ("4", time + ".000000")),
-        ]
-        self.assertEqual(expected, diff)
+        }
+        self.assertEqual(expected, set(diff))
+        keys = [k for _, (k, _) in diff]
+        assert keys[0] == keys[1] and keys[2] == keys[3]    # same keys
 
     def test_dup_pks(self):
         time = "2022-01-01 00:00:00"