Quarantine pypi package registry spec

What does this MR do and why?

This MR quarantines qa/qa/specs/features/browser_ui/5_package/package_registry/pypi_repository_spec.rb because of gitlab-org/quality/engineering-productivity/master-broken-incidents#7046 (closed). It is already fast-quarantined and the underlying issue seems to be resolved but we need a long-term quarantine to check with an MR if we can unquarantine.

See #469067 (closed)