Drop Gerrit log cleanup cron from Ansible

Now that Ansible has removed the cron job from the review node we can
remove the management of the cronjob from Ansible. This is step 2 in a
two step process. This should only merge after step 1 has landed and
been applied to the review server.

Change-Id: If8fd5bf83394a9caf2c3878311995437d241cf6d

playbooks/roles/gerrit/tasks/main.yaml

@@ -347,17 +347,6 @@
     minute: 17
     hour: 4
 
-# Gerrit rotates logs on its own now. Clean up our old cron job that did it
-# before.
-- name: Set up cron job to clean old gerrit logs
-  cron:
-    name: clear-gerrit-logs
-    state: absent
-    user: gerrit2
-    job: 'find /home/gerrit2/review_site/logs/*.gz -mtime +30 -exec rm -f {} \;'
-    minute: 1
-    hour: 6
-
 - name: Setup db backups
   include_tasks: backup.yaml