Airship SDK 15: DeepLinkDelegate is ambiguous for type lookup

The clean fix is to upgrade to Airship SDK 16, where the module was renamed from Airship to AirshipKit, removing the collision, and also update the Apptimize SDK to 3.5.3, which fixed their side. The reporter confirmed the upgrade resolved it.

Source: https://github.com/urbanairship/ios-library/issues/294