Get rid of github.com/k0sproject/k0s as a dependency

[juanluisvaladas]

K0smotron relies on k0s and we've seen some CVEs on some dependencies which we ignored entirely because they are only used in the tests and have no actual impact. However, we haven't updated this in a while and it's a matter of time that one dependency that we share has a CVE or that we can't bump at some point and becomes an actual issue.

For these reasons we thought we should keep k0s updated but #703 has shown that this is a very big and risky change as many things could go wrong. We agreed that the long term goal is removing github.com/k0sproject/k0s as a code dependency entirely.

This is a tracking issue to see where we have dependencies to it:

• inttest/basic/basic_test.go
• inttest/capi-controlplane-docker-downscaling/capi_controlplane_docker_downscaling_test.go
• inttest/capi-controlplane-docker-tunneling-proxy/capi_controlplane_docker_tunneling_proxy_test.go
• inttest/capi-controlplane-docker-tunneling/capi_controlplane_docker_tunneling_test.go
• inttest/capi-controlplane-docker-worker/capi_controlplane_docker_worker_test.go
• inttest/capi-controlplane-docker/capi_controlplane_docker_test.go
• inttest/capi-docker-clusterclass-k0smotron/capi_docker_clusterclass_k0smotron_test.go
• inttest/capi-docker-clusterclass/capi_docker_clusterclass_test.go
• inttest/capi-docker-machine-template-update/capi_docker_machine_template_update_test.go
• inttest/capi-docker-machinedeployment/capi_docker_test.go
• inttest/capi-docker/capi_docker_test.go
• inttest/capi-remote-machine-job-provision/capi_remote_machine_job_provision_test.go
• inttest/capi-remote-machine-template-update/capi_remote_machine_template_update_test.go
• inttest/capi-remote-machine-template/capi_remote_machine_template_test.go
• inttest/capi-remote-machine/capi_remote_machine_test.go
• inttest/config-update-hcp/config_update_test.go
• inttest/ha-controller-etcd/ha_controller_etcd_test.go
• inttest/ha-controller-secret/ha_controller_secret_test.go
• inttest/ha-controller/ha_controller_test.go
• inttest/hostpath/hostpath_test.go
• inttest/jointoken/jointoken_test.go
• inttest/monitoring/monitoring_test.go
• inttest/pvc/pvc_test.go
• inttest/scaling-etcd/scaling_etcd_test.go

The two use cases I've identified are:
1- check-basic uses BootLooseSuite as a base framework, which is quite complex to deal with
2- Many checks use specific tests such as WaitForNodeReadyStatus which should be pretty self contained and small enough that we're comfortable just copying and pasting into the code.