Disable verify entity integrity mapreduce on sandbox

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=192289233

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

@@ -196,6 +196,8 @@
     <target>backend</target>
   </cron>
 
+  <!--
+    TODO(b/71607184): Consider re-enabling once load-testing-related entities are cleared out.
   <cron>
     <url><![CDATA[/_dr/cron/fanout?queue=retryable-cron-tasks&endpoint=/_dr/task/verifyEntityIntegrity&runInEmpty]]></url>
     <description>
@@ -205,5 +207,6 @@
     <timezone>UTC</timezone>
     <target>backend</target>
   </cron>
+  -->
 
 </cronentries>