E2E: Quarantine unlocking job artifacts test

What does this MR do?

This MR quarantines qa/qa/specs/features/browser_ui/4_verify/ci_job_artifacts/unlocking_job_artifacts_across_parent_child_pipelines_spec.rb due to an increase in failures over the past week.

A few workarounds have already been attempted, such as !133166 (merged) to increase the wait time for artifacts, but the test continued to fail even with the increase.

E2E Test Failure issue(s)

#422863 (closed)

Check-list

• General code guidelines check-list
  • Code review guidelines
  • Style guides
• Quarantine test check-list
  • Follow the Quarantining Tests guide.
  • Confirm the test has a quarantine: tag with the specified quarantine type.
  • Note if the test should be quarantined for a specific environment.
  • (Optionally) In case of an emergency (e.g. blocked deployments), consider adding labels to pick into auto-deploy (Pick into auto-deploy priority1 severity1).
• Dequarantine test check-list
  • Follow the Dequarantining Tests guide.
  • Confirm the test consistently passes on the target GitLab environment(s).
• To ensure a faster turnaround, ask in the #quality_maintainers Slack channel for someone to review and merge the merge request, rather than assigning it directly.