The deferred_work events can't be processed in the test suite
environment, since it tries to make requests to the host <realm.uri>
which is "zulip.testserver" and obviously not going to work. Since the
test suite base data set has no animated emoji, there's nothing to do,
and we can skip this step.
This code only runs when applying the migration to an already
provisioned test db - because during an initial db set up there are no
realms yet, so no events get pushed by the migration.