gh-132719: Skip multiprocessing test if missing ctypes (#132846)

Skip test_rlock_locked_2processes() if multiprocessing.sharedctypes
is missing (need ctypes).

Author: vstinner

Lib/test/_test_multiprocessing.py

@@ -1601,6 +1601,7 @@ def test_rlock(self):
         self.assertFalse(lock.locked())
         self.assertRaises((AssertionError, RuntimeError), lock.release)
 
+    @unittest.skipUnless(HAS_SHAREDCTYPES, 'needs sharedctypes')
     def test_rlock_locked_2processes(self):
         if self.TYPE != 'processes':
             self.skipTest('test not appropriate for {}'.format(self.TYPE))