integration_test and flutter drive tests are flaky when running with --web-renderer=canvaskit --debug.

This is because there's an incompatibility between CanvasKit's and DDC's module loading systems. Both use requireJS, but there's a race that doesn't resolve cleanly.

Work is already underway on the Dart SDK side: dart-lang/sdk#55429.

This issue is for tracking the Flutter-side changes.

This issue will supersede #146189. The P0 will be solved by temporarily turning off --debug mode test shards.