update cron yml so that script can properly reference config

kubernetes/corp_user_groups_cron_sync.yml

@@ -23,6 +23,9 @@ spec:
                 secretKeyRef:
                   name: eras-production
                   key: rails-master-key
-            command: ['ruby', './scripts/user_group_membership_classification_backfill.rb']
+            command:
+            - /bin/sh
+            - -c
+            - cd scripts; ruby user_group_membership_classification_backfill.rb
           restartPolicy: Never
       backoffLimit: 2