(pytest) don't run redundant tests in cpu suite (#1532)

tank/test_models.py

@@ -64,6 +64,7 @@ def get_valid_test_params():
         device
         for device in get_supported_device_list()
         if not check_device_drivers(device)
+        and device not in ["cpu-sync", "cpu-task"]
     ]
     dynamic_list = (True, False)
     # TODO: This is soooo ugly, but for some reason creating the dict at runtime