This also adds support for installing python3-docker (not python-docker) in systems that run Python 3.
Raspbian doesn't seem to support arm64, so this is somewhat pointless right now. However, they might in the future. Doing this should also unify us some more with `setup_debian.yml` with the ultimate goal of eliminating `setup_raspbian.yml`.
It's likely installed by default, but it doesn't hurt to specify it. It also makes us more the same with `setup_debian.yml`.