test_json: fix reentrant JSONDecodeError test

Author: VanshAgarwal24036

Lib/test/test_json/test_fail.py

@@ -1,4 +1,5 @@
 from test.test_json import PyTest, CTest
+from test import support
 import json
 import sys
 
@@ -267,6 +268,8 @@ def __call__(self, *args, **kwargs):
             self.assertEqual(sys.getrefcount(hook), 3)
             del hook
 
+            support.gc_collect()
+            
             with self.assertRaises(TypeError):
                 json.loads('"\\uZZZZ"')
         finally: