As mentioned in https://github.com/mperham/sidekiq/wiki/Error-Handling,
Sidekiq can be configured with an exception handler. We use this to log
the exception in a structured way so that `corrrelation_id`, `class`,
and other useful fields are available.

The previous error backtrace in the `StructuredLogger` class did not
provide useful information because Sidekiq swallows the exception and
raises a `JobRetry::Skip` exception.

Closes https://gitlab.com/gitlab-org/gitlab/issues/29425