Idempotent role

The role is idempotent. For example, if Poudriere is configured to build packages for two architectures

poudriere_pkg_arch: [amd64, arm]

there should be no changes reported when the playbook is run repeatedly with the same data

shell> ANSIBLE_DISPLAY_OK_HOSTS=false ANSIBLE_DISPLAY_SKIPPED_HOSTS=false ansible-playbook pb.yml

PLAY [build.example.com] *******************************************************************************
included: /home/admin/.ansible/roles/vbotka.freebsd_poudriere/tasks/pkglist.yml for build.example.com => (item=amd64)
included: /home/admin/.ansible/roles/vbotka.freebsd_poudriere/tasks/pkglist.yml for build.example.com => (item=arm)

PLAY RECAP *********************************************************************************************
build.example.com: ok=13   changed=0    unreachable=0    failed=0    skipped=12   rescued=0    ignored=0