Add package_info_plus dependency

Added the package_info_plus dependency (version ^9.0.0) to pubspec.yaml to enable access to app package information.

{{cookiecutter.out_dir}}/pubspec.yaml

@@ -36,6 +36,7 @@ dependency_overrides:
       path: src/serious_python
 
   wakelock_plus: ^1.4.0
+  package_info_plus: ^9.0.0
   window_manager: ^0.5.1
 
 # {% if 'flet_geolocator' in cookiecutter.flutter.dependencies %}