Support Swift Package Manager (SPM) for iOS and macOS

Hi 👋 Thanks for maintaining cupertino_http — it’s been very useful. Flutter currently warns that cupertino_http does not support Swift Package Manager (SPM) on both iOS and macOS, and notes that this will become a build error in a future Flutter release. Current warning: The following plugins do not support Swift Package Manager for ios: - cupertino_http This will become an error in a future version of Flutter. The following plugins do not support Swift Package Manager for macos: - cupertino_http This will become an error in a future version of Flutter. Would it be possible to add Swift Package Manager support for iOS and macOS? This would help Flutter projects stay compatible with upcoming releases and align with Flutter’s migration toward built-in package management. Thanks again for your work on this package.