databases/pgbouncer: Update to 1.18.0

Maintainer yields maintainership in favor of submitter, already maintainer of
several ports.

ChangeLog: https://www.pgbouncer.org/changelog.html#pgbouncer-118x

• Add application_name to SHOW CLIENTS/SERVERS/SOCKETS output
• Add information about cancel requests to SHOW CLIENTS/SERVERS/POOLS output
• Fail sbuf_send_pending operation if destination socket is closed
• Fix a few possible crashes
• Fix for overflow bug in comma-separated host list feature, causing connection to get re-routed to Unix socket
• Don’t evict connections to achieve min_pool_size
• Fix SHOW HELP with PostgreSQL 15
• Fix race condition in query cancelation handling. It was possible that a query cancellation for one client canceled a query for another one. This could happen when a cancel request was received by PgBouncer when the query it was meant to cancel already completed by itself.
• Various CI updates

PR: 269499
Reported by: dmitry.wagin@ya.ru
Approved by: m.tsatsenko@gmail.com (maintainer)