Port automation to strip App Clip from Enterprise target to `release-toolkit`

[mokagio]

See duplication between Automattic/Gravatar-SDK-iOS#659 and Automattic/pocket-casts-ios#2617 + Automattic/pocket-casts-ios#2618

The logic works well as a function in the Fastfile of those apps, but I suppose the idiomatic Fastlane thing to do would be to make it an action.

One case against doing this is that we have the code in only two apps. We might want to wait for a third client (a la Three Strikes And You Automate or for the need to update the logic.