Change docker generation to not require DIND and publish in this registry

Right now, the onionmasq container is built somewhere else and then the container is published in the registry there.

The reason that was done originally was because the container is built using DiND (Docker-in-Docker). That requires a special privileged runner that can do DiND, and none of the Tor runners provide that functionality.

However, we have been able to get around DiND build requirements by using kaniko instead, and so we should change how we are building the container to use a non-DiND method, and then we can move it to be inside the Tor gitlab CI and published into the registry here.