add removed var validation to validate_inventory (#12942)

roles/validate_inventory/tasks/main.yml

@@ -6,6 +6,15 @@
 # -> nothing depending on facts or similar cluster state
 # Checks depending on current state (of the nodes or the cluster)
 # should be in roles/kubernetes/preinstall/tasks/0040-verify-settings.yml
+- name: Fail if removed variables are used
+  vars:
+    removed_vars: []
+    removed_vars_found: "{{ query('varnames', '^' + (removed_vars | join('|')) + '$') }}"
+  assert:
+    that: removed_vars_found | length == 0
+    fail_msg: "Removed variables present: {{ removed_vars_found | join(', ') }}"
+  run_once: true
+
 - name: Stop if kube_control_plane group is empty
   assert:
     that: groups.get( 'kube_control_plane' )