Add Swift Package Manager Support

[alejandro-all-win-software]

DESCRIPTION

• Added support for Swift Package Manager for compatibility with new projects.
• Updated podspec.
• Closes Add Swift Package Manager support #364

[alejandro-all-win-software]

Currently blocked by this: flutter/flutter#161182

[mendoxe]

Any updates on this?

[yanashenyang]

The following plugins do not support Swift Package Manager for ios:

• appsflyer_sdk
  This will become an error in a future version of Flutter. Please contact the plugin maintainers to request Swift Package Manager adoption.

[jamalalayeq]

After I updated to Flutter 3.44.1, I am facing this issue.

The following plugins do not support Swift Package Manager for ios:
  - appsflyer_sdk
This will become an error in a future version of Flutter. Please contact the plugin maintainers to request Swift Package Manager adoption.

[rydmike]

Agreed with others here, with the release of Flutter 3.44, AppsFlyer needs to move forward on the SPM support. Facing same issue as others reported. Still the mixed mode with old pods still work, so it is not critical - yet

[alejandro-all-win-software]

Currently blocked by this: flutter/flutter#161182

This is still blocked by the issue mentioned above, so there's nothing more I can do on my end for now. If you find another way to opt in to the Purchase Connector functionality, I'd be happy to close this PR in favor of that approach.