Fix some issues in the test code found by np2.0.0 (#5621) (#5632)

Co-authored-by: Jianfeng Mao <4297243+jmao-denver@users.noreply.github.com>

py/client/tests/test_table.py

@@ -332,7 +332,7 @@ def test_agg_with_options(self):
  self.assertEqual(rt.size, test_table.select_distinct(["c"]).size)
 
  with self.assertRaises(TypeError):
- aggs = [unique(cols=["ua = a", "ub = b"], include_nulls=True, non_unique_sentinel=np.uint32(-1))]
+ aggs = [unique(cols=["ua = a", "ub = b"], include_nulls=True, non_unique_sentinel=np.uint32(128))]
 
  aggs_default = [
  median(cols=["ma = a", "mb = b"]),

py/server/tests/test_numpy.py

@@ -58,7 +58,7 @@ def setUp(self):
  "NPLong": np.array([1, -1], dtype=np.int8),
  "Float": np.array([1.01, -1.01], dtype=np.float32),
  "Double": np.array([1.01, -1.01]),
- "String": np.array(["foo", "bar"], dtype=np.string_),
+ "String": np.array(["foo", "bar"], dtype=np.str_),
  "Datetime": np.array([1, -1], dtype=np.dtype("datetime64[ns]")),
  "PyObj": np.array([CustomClass(1, "1"), CustomClass(-1, "-1")]),
  "PyObj1": np.array([[1, 2, 3], CustomClass(-1, "-1")], dtype=np.object_),

py/server/tests/test_pandas.py

@@ -235,7 +235,7 @@ def test_arrow_backend(self):
  ),
  'pa_byte': pandas.Series([1, None], dtype='int8[pyarrow]'),
  'py_string': pandas.Series(['text1', None], dtype=pd.StringDtype()),
- 'pa_byte1': pandas.Series(np.array([1, 255], dtype=np.int8)),
+ 'pa_byte1': pandas.Series(np.array([1, 127], dtype=np.int8)),
  })
  dh_table = to_table(df)
  self.assertEqual(dh_table.to_string().count('null'), 5)