Support structured logging for sidekiq exporter
sidekiq exporter was moved to a separate logfile in gitlab-foss!18127 (merged) when support for json logs was added to sidekiq gitlab-foss#20060 (closed).
Now that sidekiq is run in a pod for cloud native installs and soon gitlab.com we will want to include the exporter logs alongside our sidekiq logs. This is not going to work currently because sidekiq exporter logs are not formatted for json and we are running the exporter in the pod.