[batch] handle events with no operation (#9820)
[batch] handle events with no operation (#9820)

These are always delete operations that have failed due to the worker not
existing.
hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail,hail-is/hail