remove-node playbook will always fail for non-etcd nodes

[lhw]

Environment:

• Cloud provider or hardware configuration:
  /
• OS (printf "$(uname -srm)\n$(cat /etc/os-release)\n"):
  CI Container: Debian GNU/Linux bullseye/sid
• Version of Ansible (ansible --version):
  2.9.6
• Version of Python (python --version):
  3.8.2

Kubespray version (commit) (git rev-parse --short HEAD):
2.14.0

Network plugin used:
Calico CNI

Full inventory with variables (ansible -i inventory/sample/inventory.ini all -m debug -a "var=hostvars[inventory_hostname]"):

Command used to invoke ansible:
ansible-playbook remove-node.yml -e "node=somenodes.at.local.domain,morenodes" -e "delete_nodes_confirmation=yes"

Output of ansible run:

fatal: [somenode.at.local.domain]: FAILED! => {
    "assertion": "node_ip is defined and node_ip | length > 0",
    "changed": false,
    "evaluated_to": false,
    "msg": "Etcd node ip is not set !"
}

Anything else do we need to know:
The change in #6603 did not include the lines

when:
  - inventory_hostname in groups['etcd']

so the remove-node playbook will always fail for non-etcd nodes.
I could quickly create a PR to fix the issue.