Update test_py_config_isoloated_per_interpreter()

Author: vstinner

Lib/test/test_capi/test_misc.py

@@ -2147,22 +2147,19 @@ def test_py_config_isoloated_per_interpreter(self):
         # This test could verify ANY config value, it just happens to have been
         # written around the time of int_max_str_digits. Refactoring is okay.
         code = """if 1:
-        import sys, _testinternalcapi
+        import sys, _testcapi
 
         # Any config value would do, this happens to be the one being
         # double checked at the time this test was written.
-        config = _testinternalcapi.get_config()
-        config['int_max_str_digits'] = 55555
-        config['parse_argv'] = 0
-        _testinternalcapi.set_config(config)
-        sub_value = _testinternalcapi.get_config()['int_max_str_digits']
+        _testcapi.config_set('int_max_str_digits', 55555)
+        sub_value = _testcapi.config_get('int_max_str_digits')
         assert sub_value == 55555, sub_value
         """
-        before_config = _testinternalcapi.get_config()
-        assert before_config['int_max_str_digits'] != 55555
+        before_config = _testcapi.config_get('int_max_str_digits')
+        assert before_config != 55555
         self.assertEqual(support.run_in_subinterp(code), 0,
                          'subinterp code failure, check stderr.')
-        after_config = _testinternalcapi.get_config()
+        after_config = _testcapi.config_get('int_max_str_digits')
         self.assertIsNot(
                 before_config, after_config,
                 "Expected get_config() to return a new dict on each call")