chore: update intl package version for localization improvements

- Upgraded intl package from version 0.19.0 to 0.20.2 in pubspec.yaml to leverage new features and enhancements for better localization support.

Author: jjoonleo

pubspec.yaml

@@ -82,7 +82,7 @@ dependencies:
   google_sign_in_platform_interface: ^2.5.0
   widgetbook: ^3.11.0
   widgetbook_annotation: ^3.3.0
-  intl: ^0.19.0
+  intl: ^0.20.2