Dependency conflict between firebase_notifications_handler and firebase_messaging

[magamine]

Because firebase_notifications_handler >=2.0.0 depends on firebase_messaging ^15.1.2
and gpep depends on firebase_messaging ^16.0.0, firebase_notifications_handler >=2.0.0 is forbidden.

So, because gpep depends on firebase_notifications_handler ^2.0.2+1, version solving failed.
Failed to update packages.