test_unsorted_segment_ops needs tf-2.3 or better (#1305)

Signed-off-by: guschmue <[email protected]>

Author: guschmue

tests/test_backend.py

@@ -1532,6 +1532,7 @@ def func(data, indices, segments):
             self._run_test_case(func, [_OUTPUT], {_INPUT: data_val, _INPUT1: indices_val, _INPUT2: segs_val})
 
     @check_opset_min_version(9, "OneHot")
+    @check_tf_min_version("2.3", "needs tf 2.3")
     def test_unsorted_segment_ops(self):
         tf_ops = [
             tf.math.unsorted_segment_max,