A regression was introduced by this commit that made ZyncWorker arguments incorrectly serialized under some conditions.

The arguments are serialized into a JSON string and are shown like this in Sidekiq:

"063cce4a-47e8-47b4-9311-8939a14da1fb", "{\"type\":\"Application\",\"id\":446,\"parent_event_id\":\"fa7098ed-b835-4a29-b3be-361c64682bd9\",\"parent_event_type\":\"Applications::ApplicationUpdatedEvent\",\"tenant_id\":2,\"service_id\":32}"

And when trying to process this job, the Zync client sends an HTTP request with the body that get serialized to JSON again (so, double serialization), and Zync responds with an error:

ZyncWorker::InvalidResponseError: Expected successful response. Got 400