Simplify usage of pre-remove role (#8334)

- Use builtin task scheduling of ansible (same task on each host)
  instead of manual looping on master

Benefits:
- One less play in remove-node.yml playbook
- Parralel node drain
- Drain parameters (timeout, grace period, retries,
  allow_ungraceful_removal) can be adjusted separately for each node
  with ansible variables

roles/remove-node/pre-remove/tasks/main.yml

@@ -14,14 +14,12 @@
       --ignore-daemonsets
       --grace-period {{ drain_grace_period }}
       --timeout {{ drain_timeout }}
-      --delete-emptydir-data {{ hostvars[item]['kube_override_hostname']|default(item) }}
-  loop: "{{ node.split(',') | default(groups['kube_node']) }}"
+      --delete-emptydir-data {{ kube_override_hostname|default(inventory_hostname) }}
   # ignore servers that are not nodes
-  when: hostvars[item]['kube_override_hostname']|default(item) in nodes.stdout_lines
+  when: kube_override_hostname|default(inventory_hostname) in nodes.stdout_lines
   register: result
   failed_when: result.rc != 0 and not allow_ungraceful_removal
   delegate_to: "{{ groups['kube_control_plane']|first }}"
-  run_once: true
   until: result.rc == 0 or allow_ungraceful_removal
   retries: "{{ drain_retries }}"
   delay: "{{ drain_retry_delay_seconds }}"