Revert magento#27391 changes

Status field is no longer used in that query after this PR

Author: driskell

app/code/Magento/Cron/etc/db_schema.xml

@@ -26,9 +26,5 @@
             <column name="status"/>
             <column name="scheduled_at"/>
         </index>
-        <index referenceId="CRON_SCHEDULE_SCHEDULE_ID_STATUS" indexType="btree">
-            <column name="schedule_id"/>
-            <column name="status"/>
-        </index>
     </table>
 </schema>