* Update dart.yml
Update Dart starter workflow to use `setup-dart` from the Dart team. This enables testing on more operating systems (Linux, Windows, and macOS), and offers more control over the Dart SDK version to test with.
* Update dart.yml
Add required disclaimer
* Update ci/dart.yml
Co-authored-by: Josh Gross <[email protected]>
Co-authored-by: Josh Gross <[email protected]>
