Dequarantine push_rules_spec example

What does this MR do?

Dequarantines rejects non-member users example from ee/browser_ui/3_create/repository/push_rules_spec.rb that has been passing reliably in the past 4 months.

E2E Test Failure issue(s)

See #224465 (closed)

Check-list

• General code guidelines check-list
  • Code review guidelines
  • Style guides
• Dequarantine test check-list
  • Follow the Dequarantining Tests guide.
  • Confirm the test consistently passes on the target GitLab environment(s).