pythongh-125451: Skip concurrent.futures test_processes_terminate()

The test hangs randomly. It tries to serialize local lock and a local
function which are not possible.

Lib/test/test_concurrent_futures/test_shutdown.py

@@ -253,6 +253,9 @@ def test_cancel_futures_wait_false(self):
 
 
 class ProcessPoolShutdownTest(ExecutorShutdownTest):
+    # gh-125451: 'lock' cannot be serialized, the test is broken
+    # and hangs randomly
+    @unittest.skipIf(True, "broken test")
     def test_processes_terminate(self):
         def acquire_lock(lock):
             lock.acquire()