fix/ansible-core 2.19: etcd: avoid mutating methods in template (#13474)

2.19 disallow methods with side effects in Jinja. Use a simple loop by
adding all the SANs source in one list.

Also check the sources before hand for failing on CIDR notation.

Link: https://github.com/ansible/ansible/issues/85202

roles/validate_inventory/tasks/main.yml

@@ -170,6 +170,7 @@
       - etcd_deployment_type in ['host', 'docker', 'kubeadm']
       - etcd_deployment_type in ['host', 'kubeadm'] or container_manager == 'docker'
       - container_manager in ['docker', 'crio', 'containerd']
+      - etcd_cert_alt_ips | reject('ansible.utils.ip_address') == []
     msg: The selected choice is not supported
   run_once: true