cleanup: Remove expired ports:

2023-05-31 net-mgmt/zabbix62-agent: Will reach end of life on 2023-05-31
2023-05-31 net-mgmt/zabbix62-frontend: Will reach end of life on 2023-05-31
2023-05-31 net-mgmt/zabbix62-java: Will reach end of life on 2023-05-31
2023-05-31 net-mgmt/zabbix62-proxy: Will reach end of life on 2023-05-31
2023-05-31 net-mgmt/zabbix62-server: Will reach end of life on 2023-05-31