I went to "Hardened Images Catalog" and searched for pgbouncer, not found (https://hub.docker.com/hardened-images/catalog?search=pgboun...)
There's a "Make a request" button, but it links to this 404-ing GitHub URL: https://github.com/docker-hardened-images/discussion/issues
oh well. hope its good stuff otherwise.
Thanks for reporting, team is fixing it, the right url is: https://github.com/docker-hardened-images/catalog/issues/