fix TAP test (#21515)

Author: divyashreepathihalli

keras/src/layers/preprocessing/image_preprocessing/rand_augment_test.py

@@ -126,4 +126,4 @@ def test_graph_issue(self):
         for output in ds:
             key_list.append(output["layer_idxes"])
 
-        self.assertNotEquals(len(np.unique(key_list)), 1)
+        self.assertNotEqual(len(np.unique(key_list)), 1)