Rename vault files

group_vars/all/vault_arch-boxes.yml

group_vars/all/vault_archweb.yml

group_vars/all/vault_archwiki.yml

group_vars/all/vault_flyspray.yml

group_vars/all/vault_kanboard.yml

group_vars/all/vault_mariadb.yml

group_vars/all/vault_matrix.yml

group_vars/all/vault_patchwork.yml

group_vars/all/vault_postgres.yml

group_vars/all/vault_security_tracker.yml

group_vars/all/vault_zabbix_server.yml

host_vars/luna.archlinux.org/vault_mariadb.yml