pythongh-108963: using random to generate unique string in sys.intern test (python#109491)

(cherry picked from commit 44b1e4e)

Author: aisk

Lib/test/test_sys.py

@@ -4,6 +4,7 @@
 import locale
 import operator
 import os
+import random
 import struct
 import subprocess
 import sys
@@ -19,10 +20,6 @@
 import warnings
 
 
-# count the number of test runs, used to create unique
-# strings to intern in test_intern()
-INTERN_NUMRUNS = 0
-
 DICT_KEY_STRUCT_FORMAT = 'n2BI2n'
 
 class DisplayHookTest(unittest.TestCase):
@@ -685,10 +682,8 @@ def test_43581(self):
         self.assertEqual(sys.__stdout__.encoding, sys.__stderr__.encoding)
 
     def test_intern(self):
-        global INTERN_NUMRUNS
-        INTERN_NUMRUNS += 1
         self.assertRaises(TypeError, sys.intern)
-        s = "never interned before" + str(INTERN_NUMRUNS)
+        s = "never interned before" + str(random.randrange(0, 10**9))
         self.assertTrue(sys.intern(s) is s)
         s2 = s.swapcase().swapcase()
         self.assertTrue(sys.intern(s2) is s)