chore(deps): bump firebase_messaging

Bumps [firebase_messaging](https://github.com/firebase/flutterfire/tree/main/packages/firebase_messaging) from 14.7.10 to 15.1.2.
- [Release notes](https://github.com/firebase/flutterfire/releases)
- [Commits](https://github.com/firebase/flutterfire/commits/firebase_messaging-v15.1.2/packages/firebase_messaging)

---
updated-dependencies:
- dependency-name: firebase_messaging
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

packages/notifications_client/firebase_notifications_client/pubspec.yaml

@@ -8,7 +8,7 @@ environment:
   flutter: ^3.22.0
 
 dependencies:
-  firebase_messaging: ^14.7.10
+  firebase_messaging: ^15.1.2
   flutter:
     sdk: flutter
   notifications_client: