Apple this week released the full and final version of iOS 27. 1, but it is only available for the foldable iPhone Duo that launched today. iPhone Duo already ships with iOS 27. 1 preinstalled, but users need to update to a newer build of iOS 27. 1 while setting up the device, and that newer build is available for download as an IPSW file as of Thursday. Apple’s release notes for the newer build simply mention unspecified "bug fixes for your iPhone." iOS 27. 1 has no security fixes . Apple jumped ahead to an iOS 27. 2 beta for all other compatible iPhone models, and the iOS 27…