Revert "[tool] tools/find_builders.dart cbuild opt in"

This reverts commit 86c41c9.

Reason for revert: This builder is now included by default

Original change's description:
> [tool] `tools/find_builders.dart` cbuild opt in
>
> Opt in to CBuild being green.
>
> Remove denylisted bots now that issue is resolved.
>
> Change-Id: I89c23720eaed78b317067bbdb065fe0cef8ecd75
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/356022
> Commit-Queue: Daco Harkes <dacoharkes@google.com>
> Reviewed-by: William Hesse <whesse@google.com>

Change-Id: Ife49afc47f576901d2b8bb5523d2c8ed5224a761
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/359862
Auto-Submit: Oleh Prypin <oprypin@google.com>
Commit-Queue: Jonas Termansen <sortie@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Jonas Termansen <sortie@google.com>

tools/find_builders.dart

@@ -33,7 +33,6 @@ Future<void> main(List<String> args) async {
     ..sort();
 
   final gerritTryList = builders.map((b) => '$b-try').join(',');
-  print('Cq-Include-Trybots: dart-internal/g3.dart-internal.try:g3-cbuild-try');
   print('Cq-Include-Trybots: dart/try:$gerritTryList');
 }