Allow in-app purchases in TestFlight sandbox

[keeshux]

Restrict beta by cutting connection rather than features

Users should be unable to open expired TestFlight builds:

https://www.reddit.com/r/ApolloAppBeta/comments/pyb00s/comment/hetbh5j/?utm_source=share&utm_medium=web3x&utm_name=web3xcss&utm_term=1&utm_content=share_button

If that's the case, just allow in-app purchases in beta and get rid of the deprecated receipt complications.

AppTransaction finally makes it possible to get rid of local receipt URL:

• https://developer.apple.com/documentation/storekit/apptransaction
• https://developer.apple.com/documentation/storekit/supporting_business_model_changes_by_using_the_app_transaction

Beware that the copied release receipt to the tunnel may be OUTDATED! Make sure to only rely on it in .beta