Add concourse as the foundational CI tool to k8s-cluster

This change allows to add a concourse-server to the kubernetes cluster.

roles/k8s-setup/defaults/main.yml

@@ -1,6 +1,8 @@
 cert_manager_state: present
 cert_manager_version: v1.18.2
+
 letsencrypt_clusterissuers: {}
+
 gitea_chart_version: 12.3.0
 gitea_state: present
 gitea_image_rootless: False
@@ -9,3 +11,8 @@ gitea_image: gitea-for-nehrke-info
 gitea_image_tag: latest
 gitea_image_registry: docker.nehrke.info
 
+concourse_chart_version: 19.0.2
+concourse_state: present
+concourse_namespace: concourse
+concourse_local_users: {}
+concourse_worker_replicas: 2