TestStackCoreScriptedProcess.py is timing out, skip it

The x86_64 macOS CI bot is failing because this test
times out.  It was marked as expectedFail earlier today,
but that's not considered a fail so the CI runs are
red.  Skipping it on Darwin for now until Ismail can
look into it.

lldb/test/API/functionalities/scripted_process/TestStackCoreScriptedProcess.py

@@ -35,7 +35,7 @@ class StackCoreScriptedProcesTestCase(TestBase):
     @skipIfOutOfTreeDebugserver
     @skipIfRemote
     @skipIfAsan  # On ASAN builds, this test times-out (rdar://98678134)
-    @expectedFailureDarwin
+    @skipIfDarwin
     def test_launch_scripted_process_stack_frames(self):
         """Test that we can launch an lldb scripted process from the command
         line, check its process ID and read string from memory."""