Engine->framework roller blocked due to test failures related to Dart SDK hot reload and debugging

Various tooling-related tests are failing with errors that appear to involve Dart hot reload and debugging.

(example: https://github.com/flutter/flutter/pull/140066)

This appears to have started with this Dart roll: https://github.com/flutter/engine/pull/48961