fix E301 'Commands should not change things if nothing needs doing'

playbooks/tasks/fetch-borg-keys.yml

playbooks/tasks/reencrypt-vault-key.yml

playbooks/tasks/sync-ssh-hostkeys.yml

roles/borg-client/tasks/main.yml

roles/borg-server/tasks/main.yml

roles/dbscripts/tasks/main.yml

roles/install_arch/tasks/main.yml

roles/opendkim/tasks/main.yml

roles/rsync_net/tasks/main.yml

roles/security_tracker/tasks/main.yml

roles/spampd/tasks/main.yml

roles/sudo/tasks/main.yml