bump version in pubspec to 15.1.3

Author: MaikuB

Diff for: flutter_local_notifications/pubspec.yaml

@@ -2,7 +2,7 @@ name: flutter_local_notifications
 description: A cross platform plugin for displaying and scheduling local
   notifications for Flutter applications with the ability to customise for each
   platform.
-version: 15.1.2
+version: 15.1.3
 homepage: https://github.com/MaikuB/flutter_local_notifications/tree/master/flutter_local_notifications
 issue_tracker: https://github.com/MaikuB/flutter_local_notifications/issues