Set database owner to fix PG 15+ schema permissions

PostgreSQL 15+ revokes CREATE on the public schema from all users
except the database owner. Without setting owner, the database is
owned by postgres and the candlepin user cannot create tables.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: zjhuntin

manifests/database/postgresql.pp

@@ -58,6 +58,7 @@
       password => postgresql::postgresql_password($db_user, $db_password),
       encoding => 'utf8',
       locale   => 'en_US.utf8',
+      owner    => $db_user,
       require  => Class['candlepin::database::postgresql::encoding'],
     }