Describe the bug
Open online interactive sample of RestorationMixin leads to 404 for

To Reproduce
Steps to reproduce the behavior:
Go to RestorationMixin
tap Open online interactive sample for RestorationMixin

Expected behavior
It should open https://api.flutter.dev/flutter/widgets/RestorationMixin-mixin.html
but it opens https://api.flutter.dev/flutter/widgets/RestorationMixin-class.html , which don't exist

Please complete the following information:

You can run the Dart: Collect Diagnostic Information command from the VS Code command palette (F1) to easily capture this information or provide it manually.

Dart Code extension: 3.87.20240402
Flutter extension: 3.87.20240402 (activated)

App: Visual Studio Code
App Host: desktop
Version: mac 1.88.0

Flutter version: Flutter (Channel master, 3.22.0-5.0.pre.59, )