fixed issue of mypy for test_ujson (pandas-dev#29022)

Author: iamrajhans

pandas/tests/io/json/test_ujson.py

@@ -1,10 +1,7 @@
-try:
-    import json
-except ImportError:
-    import simplejson as json
 import calendar
 import datetime
 import decimal
+import json
 import locale
 import math
 import re

setup.cfg

@@ -196,9 +196,6 @@ ignore_errors=True
 [mypy-pandas.tests.indexing.test_loc]
 ignore_errors=True
 
-[mypy-pandas.tests.io.json.test_ujson]
-ignore_errors=True
-
 [mypy-pandas.tests.series.test_constructors]
 ignore_errors=True