nodejs and Dart tests for TextMate grammar do not produce the same output #6131

While investigating #6130, I made the following change to the textmate grammar:

When I re-run the Dart-Code tests against this code:

/// Test
/// ```
/// this
///
void main() {}

It appears to solve the issue (at least in part):

However, reproducing the same test in the dart-syntax-highlight repo and using the Dart implementation of the parser/syntax highlighting does not produce this difference/fix.

Since changing the grammar means landing changes in the dart-syntax-highlight repo, we should find out which one is behaving correctly and try to fix the other.