Bumb flutter_quill minimum to 8.4.1

Author: Ellet

flutter_quill_extensions/pubspec.yaml

@@ -26,7 +26,7 @@ dependencies:
   flutter:
     sdk: flutter
 
-  flutter_quill: ^8.3.0
+  flutter_quill: ^8.4.1
 
   http: ^1.1.0
   photo_view: ^0.14.0