"Unable to launch Flutter project in a Dart-only workspace" when trying to launch a Flutter app added to a non-Flutter workspace #5612
Description
At around 46:00 in https://www.youtube.com/watch?v=EsklFa3nkwA, trying to run the project with CodeLens resulted in:
"Unable to launch Flutter project in a Dart-only workspace"
My guess is that the workspace was opened without a Flutter project initially, so we detected the workspace as Dart-only, and then when a Flutter project was later added, we didn't update.
When in a Dart workspace, we should watch for pubspec.yaml being updated/created and check again if this is a Flutter project. If we need to upgrade from Dart to Flutter, we need to perform an extension restart (since we may need to find a Flutter SDK whereas before we might have only had a Dart one).