[3.11] gh-108416: Mark slow but not CPU bound test methods with requires_resource('walltime') (GH-108480) (GH-108924)

(cherry picked from commit 1e0d62793a)

Lib/test/test_signal.py

@@ -745,6 +745,7 @@ class SiginterruptTest(unittest.TestCase):
         interrupted = self.readpipe_interrupted(True)
         self.assertTrue(interrupted)
 
+    @support.requires_resource('walltime')
     def test_siginterrupt_off(self):
         # If a signal handler is installed and siginterrupt is called with
         # a false value for the second argument, when that signal arrives, it