feat: support Flutter stable channel (#581)

* feat: adjust toggle list block

* chore: upgrade Flutter to master channel

* chore: upgrade pbxproj

* fix: toolbar copy button not closing on mobile editor

* fix: formatting issues and add missing commas

* chore: add stable branch to GitHub Actions workflow

* chore: add missing trailing commas

* chore: adjust indentation padding in block component
configuration and unit tests

pubspec.yaml

@@ -34,7 +34,7 @@ dependencies:
   collection: ^1.17.0
   nanoid: ^1.0.0
   visibility_detector: ^0.4.0+2
-  file_picker: ^5.3.1
+  file_picker: ^6.1.1
   path: ^1.8.3
   path_provider: ^2.0.5
   diff_match_patch: ^0.4.1
@@ -44,7 +44,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  flutter_lints: ^2.0.1
+  flutter_lints: ^3.0.1
   network_image_mock: ^2.1.1
   mockito: ^5.4.1