Move setup of foundational service from k8s to k3s

It simply doesn't make sense to split the installation of the
kubernetes-cluster from the provisioning of foundational services.
Therefore I drop the idea to organise these services in another
terraform-setup and instead ensure their presence with ansible, as it's
already responsible for setting up the cluster and keep it up-to.date.

k3s/roles/k8s-setup/defaults/main.yml

@@ -0,0 +1,3 @@
+cert_manager_state: present
+cert_manager_version: v1.18.2
+letsencrypt_clusterissuers: {}

k3s/roles/k8s-setup/tasks/main.yml

@@ -0,0 +1,29 @@
+- name: Deploy cert manager {{ cert_manager_version }}
+  kubernetes.core.helm:
+    name: cert-manager
+    chart_ref: "oci://quay.io/jetstack/charts/cert-manager"
+    chart_version: "{{ cert_manager_version }}"
+    release_namespace: "cert-manager"
+    create_namespace: True
+    release_state: "{{ cert_manager_state }}"
+    set_values:
+    - value: crds.enabled=true
+
+- name: Provide let's encrypt clusterissuers
+  kubernetes.core.k8s:
+    definition:
+      apiVersion: cert-manager.io/v1
+      kind: ClusterIssuer
+      metadata:
+        name: "letsencrypt-{{ item.key }}"
+      spec:
+        acme:
+          email: "{{ item.value.email }}"
+          privateKeySecretRef:
+            name: "letsencrypt-{{ item.key }}"
+          server: "{{ item.value.server }}"
+          solvers:
+          - http01:
+              ingress:
+                class: "traefik"
+  loop: "{{ letsencrypt_clusterissuers | dict2items }}"