Uncomment crontab entry for deleteProberData

This was only supposed to stay commented out until load-testing was complete.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=210087917

java/google/registry/env/sandbox/default/WEB-INF/cron.xml

@@ -163,9 +163,6 @@
     <target>backend</target>
   </cron>
 
-  <!--
-    Removed for the duration of load testing
-    TODO(b/71607184): Restore after loadtesting is done
   <cron>
     <url><![CDATA[/_dr/cron/fanout?queue=retryable-cron-tasks&endpoint=/_dr/task/deleteProberData&runInEmpty]]></url>
     <description>
@@ -175,7 +172,6 @@
     <timezone>UTC</timezone>
     <target>backend</target>
   </cron>
-  -->
 
   <cron>
     <url><![CDATA[/_dr/cron/fanout?queue=retryable-cron-tasks&endpoint=/_dr/task/exportReservedTerms&forEachRealTld]]></url>