[core] Update Flutter to v3.13.7 (#29)

Update the used Flutter version to 3.13.7 and update all Flutter
packages to their latest version.

app/lib/widgets/column/header/column_layout_header_settings.dart

@@ -100,7 +100,7 @@ class ColumnLayoutHeaderSettings extends StatelessWidget {
               icon: const Icon(Icons.chevron_right),
             ),
           ],
-        )
+        ),
       ],
     );
   }