Idempotency fixes to roles/pre-upgrade (#3497)

roles/upgrade/pre-upgrade/tasks/main.yml

@@ -8,6 +8,7 @@
   register: kubectl_node_ready
   delegate_to: "{{ groups['kube-master'][0] }}"
   failed_when: false
+  changed_when: false
 
 # SchedulingDisabled: unschedulable = true
 # else unschedulable key doesn't exist
@@ -18,6 +19,7 @@
   register: kubectl_node_schedulable
   delegate_to: "{{ groups['kube-master'][0] }}"
   failed_when: false
+  changed_when: false
 
 - set_fact:
     needs_cordoning: >-
@@ -37,6 +39,7 @@
   register: kubectl_version
   delegate_to: "{{ groups['kube-master'][0] }}"
   run_once: yes
+  changed_when: false
   when:
     - drain_nodes
     - needs_cordoning