Update node update config to use node id rather than magic name

roles/swarm/tasks/join.yaml

@@ -30,6 +30,12 @@
     remote_addrs: "{{ _docker_swarm_manager_addresses }}"
     join_token: "{{ _docker_swarm_join_token.stdout.strip() }}"
 
+- name: Fetch node swarm ID
+  ansible.builtin.command:
+    cmd: !unsafe docker info --format '{{ .Swarm.NodeID}}'
+  changed_when: false
+  register: _docker_node_id_raw
+
 # For newly added nodes we don't want to have services be automatically scheduled on them
 # until the configuration is complete. The node-up playbook will be responsible for updating
 # the node to make it available in the cluster again
@@ -38,4 +44,4 @@
     ansible_python_interpreter: "{{ skylab_ansible_venv }}/bin/python"
   community.docker.docker_node:
     availability: drain
-    hostname: "{{ skylab_hostname }}"
+    hostname: "{{ _docker_node_id_raw.stdout.strip() }}"