cleanup: Remove expired Bacula 11 ports:

2024-09-30 sysutils/bacula11-client: Unsupported. Please migrate to bacula15-server
2024-09-30 sysutils/bacula11-client-static: Unsupported. Please migrate to bacula15-server
2024-09-30 sysutils/bacula11-docs: Unsupported. Please migrate to bacula15-server
2024-09-30 sysutils/bacula11-server: Unsupported. Please migrate to bacula15-server
2024-09-30 net-mgmt/nagios-check_bacula11: Unsupported. Please migrate to bacula15-server