Artifact Expiration Defaults

What does this MR do?

Implement Artifact Expiration Defaults, which would be set if not given for a particular job.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated
• Screenshots added
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing

What are the relevant issue numbers?

Closes #27762 (closed)

app/controllers/admin/application_settings_controller.rb

@@ -83,6 +83,7 @@ class Admin::ApplicationSettingsController < Admin::ApplicationController
       :akismet_api_key,
       :akismet_enabled,
       :container_registry_token_expire_delay,
+      :default_artifacts_expire_in,
       :default_branch_protection,
       :default_group_visibility,
       :default_project_visibility,