Purchasing Apple TV feature may lead to blank screen and hang

[keeshux]

The app log stops at:

15:42:41.779 DEBUG ProfileManager.fixDuplicateNames():459 - No duplicated profiles
16:08:14.394 DEBUG ProductManager.refreshProducts():103 - In-app products already available, not refreshing
16:08:23.544 DEBUG ProductManager.reloadReceipt():263 - Original purchased build: 3395
16:08:23.549 DEBUG ProductManager.reloadReceipt():273 - In-app receipts:
16:08:23.552 DEBUG ProductManager.reloadReceipt():283 - 	com.algoritmico.ios.Passepartout.features.full_multi_version [purchased on: 2023-03-08 10:05:20 +0000]
16:08:23.555 INFO ProductManager.reloadReceipt():289 - Purchased features: [PassepartoutFrontend.LocalProduct(rawValue: "com.algoritmico.ios.Passepartout.features.full_multi_version")]

Probably a concurrency regression from #438, e.g. some missing callback.