gh-110017: Disable test_signal.test_stress_modifying_handlers on macOS (#112834)

Test test_stress_modifying_handlers in test_signal can crash
the interpreter due to a bug in macOS. Filed as FB13453490
with Apple.

Author: ronaldoussoren

Lib/test/test_signal.py

@@ -1318,6 +1318,7 @@ def handler(signum, frame):
         # Python handler
         self.assertEqual(len(sigs), N, "Some signals were lost")
 
+    @unittest.skipIf(sys.platform == "darwin", "crashes due to system bug (FB13453490)")
     @unittest.skipUnless(hasattr(signal, "SIGUSR1"),
                          "test needs SIGUSR1")
     @threading_helper.requires_working_threading()

Misc/NEWS.d/next/macOS/2023-12-07-15-53-16.gh-issue-110017.UMYzMR.rst

@@ -0,0 +1,2 @@
+Disable a signal handling stress test on macOS due to a bug in macOS
+(FB13453490).