Use "str" instead of pd.StringDtype(na_value=np.nan)

Author: WillAyd

pandas/tests/io/json/test_pandas.py

@@ -708,7 +708,7 @@ def test_series_roundtrip_object(self, orient, dtype, object_series):
             expected.name = None
 
         if using_string_dtype():
-            expected = expected.astype(pd.StringDtype(na_value=np.nan))
+            expected = expected.astype("str")
 
         tm.assert_series_equal(result, expected)