[in_app_purchase_storekit] Re-add reference to tests to the Mac project after bots are upgraded to Mac 14 #157065
Description
Even thought StoreKitTest is technically a mac 11 framework, the bulk of the testing features, such simulating network errors and things like that are mac 14 only. Since our fleet is part mac 13 and part mac 14 right now, the tests only pass when being run on a mac 14 bot.
We should re-add reference to tests to the Mac project after bots are upgraded to Mac 14. They just need to be referenced in place, since mac and ios share the same tests.