Bug 1488313: [taskgraph] Don't notify sherrifs on cron decision task failures on try; r=dustin

Differential Revision: https://phabricator.services.mozilla.com/D25090

--HG--
extra : moz-landing-system : lando

.taskcluster.yml

@@ -110,7 +110,7 @@ tasks:
                 kind: cron-task
 
         routes:
-          $flatten:
+          $flattenDeep:
             - "tc-treeherder.v2.${repository.project}.${push.revision}.${push.pushlog_id}"
             - $if: 'tasks_for == "hg-push"'
               then:
@@ -140,10 +140,12 @@ tasks:
                 # list each cron task on this revision, so actions can find them
                 - 'index.gecko.v2.${repository.project}.revision.${push.revision}.cron.${ownTaskId}'
                 # BUG 1500166 Notify ciduty by email if a nightly hook fails
-                - "notify.email.ciduty+failedcron@mozilla.com.on-failed"
-                - "notify.email.ciduty+exceptioncron@mozilla.com.on-exception"
-                - "notify.email.sheriffs+failedcron@mozilla.org.on-failed"
-                - "notify.email.sheriffs+exceptioncron@mozilla.org.on-exception"
+                - $if: 'repository.project != "try"'
+                  then:
+                  - "notify.email.ciduty+failedcron@mozilla.com.on-failed"
+                  - "notify.email.ciduty+exceptioncron@mozilla.com.on-exception"
+                  - "notify.email.sheriffs+failedcron@mozilla.org.on-failed"
+                  - "notify.email.sheriffs+exceptioncron@mozilla.org.on-exception"
                 # These are the old index routes for the decision task.
                 - "index.gecko.v2.${repository.project}.latest.firefox.decision-${cron.job_name}"