fix(kubeadm-init): Prepare SSH hosts during bootstrap

This patch extends the installation run, by populating the known_hosts
file of SSH before running further commands. This provides a better
hands-off install.

utils/kubernetes-init.mk

+.PHONY: ssh-init-hosts
+ssh-init-hosts:
+	ssh -o StrictHostKeyChecking=no cp01.$(TF_VAR_dns_domain) echo "Hello World"
+	ssh -o StrictHostKeyChecking=no cp02.$(TF_VAR_dns_domain) echo "Hello World"
+	ssh -o StrictHostKeyChecking=no cp03.$(TF_VAR_dns_domain) echo "Hello World"
+
 .PHONY: kubeadm-init
 kubeadm-init:
 	ssh cp01.$(TF_VAR_dns_domain) kubeadm init --control-plane-endpoint "api.$(TF_VAR_dns_domain):6443" --upload-certs --pod-network-cidr "192.168.0.0/16"
@@ -26,4 +32,5 @@ kubectl-remove-all-master-taints:
 kubectl-delete-wrong-subnet:
 	kubectl get pods --all-namespaces -o wide | grep 10.85. | awk '{print "-n " $$1 " " $$2}' | xargs -L 1 kubectl delete pod
 
-kubernetes-install: kubeadm-init kubeadm-copy-config kubectl-remove-first-master-taints flux-bootstrap kubeadm-join-masters kubectl-remove-all-master-taints kubectl-delete-wrong-subnet
+.PHONY: kubernetes-install
+kubernetes-install: ssh-init-hosts kubeadm-init kubeadm-copy-config kubectl-remove-first-master-taints flux-bootstrap kubeadm-join-masters kubectl-remove-all-master-taints kubectl-delete-wrong-subnet