Remove zabbix-agent role everywhere

We switched for monitoring to prometheus so zabbix-agent is unwanted and
we don't want to accidently deploy it again.

playbooks/all-hosts-basic.yml

@@ -12,5 +12,4 @@
     #- { role: sshd, tags: ['sshd'] }
     - { role: root_ssh }
     - { role: borg_client, tags: ["borg"], when: "'borg_clients' in group_names" }
-    - { role: zabbix_agent, tags: ["zabbix"], when: "'unmanaged' not in group_names" }
     - { role: hardening }

playbooks/archive-mirrors.yml

@@ -11,5 +11,4 @@
     - { role: nginx }
     - { role: unbound }
     - { role: syncarchive, tags: ['nginx'] }
-    - { role: zabbix_agent, tags: ["zabbix"] }
     - { role: archive, archive_nginx_only: true, archive_dir: "/srv/archive"}

playbooks/gemini.archlinux.org.yml

@@ -14,7 +14,6 @@
     - { role: root_ssh }
     - { role: borg_client, tags: ['borg'] }
     - { role: sudo, tags: ['archusers'] }
-    - { role: zabbix_agent }
     - { role: certbot }
     - { role: nginx }
     - { role: dbscripts, repos_domain: "repos.archlinux.org", repos_rsync_domain: "rsync.archlinux.org", svntogit_repos: "/srv/svntogit/repos", postgres_ssl: 'on', tags: ['archusers'] }

playbooks/homedir.archlinux.org.yml

@@ -13,4 +13,3 @@
     - { role: archusers }
     - { role: public_html, public_domain: "pkgbuild.com", tags: ['nginx'] }
     - { role: borg_client, tags: ["borg"] }
-    - { role: zabbix_agent, tags: ["zabbix"] }

playbooks/luna.yml

@@ -7,7 +7,6 @@
     - name: open firewall holes for services
       firewalld: service={{ item }} permanent=true state=enabled immediate=yes
       with_items:
-        - zabbix_agent
         - http
         - https
         - rsyncd

playbooks/matrix.archlinux.org.yml

@@ -21,5 +21,4 @@
     - role: postfix
       postfix_relayhost: "orion.archlinux.org"
     - { role: matrix }
-    - { role: zabbix_agent, tags: ["zabbix"] }
     - { role: fail2ban }

playbooks/mirrors.yml

@@ -12,5 +12,4 @@
     - { role: unbound }
     - { role: syncrepo, tags: ['nginx'] }
     - { role: archweb, archweb_site: false, archweb_services: false, archweb_mirrorcheck: true }
-    - { role: zabbix_agent, tags: ["zabbix"] }
     - { role: arch32_mirror, tags: ['nginx'] }

playbooks/state.archlinux.org.yml

@@ -11,7 +11,6 @@
     - { role: unbound }
     - { role: certbot }
     - { role: borg_client, tags: ["borg"] }
-    - { role: zabbix_agent, tags: ["zabbix"] }
     - { role: root_ssh }
     - role: postgres
       postgres_listen_addresses: "*"