ansible: prevent partial upgrades with pacman
This adds a new role that is basically a shim for ansible.builtin.pacman, that is used to install software by other roles. If the given app doesn't exist, it upgrades the pacman cache and does a full system upgrade. If given apps exist, it should skip the cache update/upgrades and will not call ansible.builtin.pacman
at all. hopefully there are no more partial upgrades!