Error building with Swift Package Manager

After migrating to SPM when using plugin flutter_appauth we got following error building the app:

`The package product 'FlutterFramework' requires minimum platform version 13.0 for the iOS platform, but this target supports 12.0`

In Xcode project settings we have iOS 15.0 everywhere as minimum deployment target
When using cocoa pods version, we got no error.

Flutter 3.41.9
flutter_appauth ^12.0.2

Start by reproducing the Flutter app build with flutter_appauth 12.0.2 through Swift Package Manager, then inspect the Xcode project settings and the plugin's package integration for the conflicting iOS deployment targets. Done means the SPM-based build succeeds without requiring an unexplained platform-version change.

Written by the indexing model from the issue text.