Adjust ProjectExportWorker urgency

ProjectExportWorker jobs are sometimes not
scheduled for >1 hour which is out of step
with customer expectations.

Changes the urgency of the worker to :low.

Changelog: changed

app/workers/all_queues.yml

@@ -2771,7 +2771,7 @@
   :worker_name: ProjectExportWorker
   :feature_category: :importers
   :has_external_dependencies:
-  :urgency: :throttled
+  :urgency: :low
   :resource_boundary: :memory
   :weight: 1
   :idempotent:

app/workers/project_export_worker.rb

@@ -8,7 +8,7 @@ class ProjectExportWorker # rubocop:disable Scalability/IdempotentWorker
 
   feature_category :importers
   worker_resource_boundary :memory
-  urgency :throttled
+  urgency :low
   loggable_arguments 2, 3
   sidekiq_options retry: false, dead: false
   sidekiq_options status_expiration: StuckExportJobsWorker::EXPORT_JOBS_EXPIRATION