Use ContainerLab for integration testing

[nemith]

Github runners now allow for nested virtualization (i.e KVM) and so using a lot more integration testing should be possible and aren't limited to just the what we can try to get running in a pure container (which isn't much).

Container labs does a good job of abstracting my vendors into a single format (matrix?) we can use. Let use that.

Existing CI intergration test are broken anyway.