Add DartDevtoolWorkflowBot to rollerAccounts (#2443)

diff --git a/auto_submit/lib/service/config.dart b/auto_submit/lib/service/config.dart
index 977c535..58ab223 100644
--- a/auto_submit/lib/service/config.dart
+++ b/auto_submit/lib/service/config.dart
@@ -197,9 +197,10 @@
         // both as we use graphQL to merge the PR and REST API to approve the PR.
         'dependabot[bot]',
         'dependabot',
+        'DartDevtoolWorkflowBot',
       };
 
-  /// The label which shows the overrideTreeStatus.
+  /// The label which shows the overrideTree    Status.
   String get overrideTreeStatusLabel => 'warning: land on red to fix tree breakage';
 
   /// Number of Pub/Sub pull calls in each cron job run.