Integration test should add k3s tests

[Mossaka]

I would like the integration test to not only work on k3d cluster, but also directly on k3s.

I know that hte node installer allows you to easily install the shim on the k3s. The ask her is to modify the make integration-test target so that it accounts for other platforms. Perhaps, we can modify it to be make test/k3d and add a new make test/k3s target that test the Spin workflows on k3s.

The main benefit of doing so is that it might be easier to debug the workflows since the containerd from k3s is directly running on your host node.