[ansible][ci] Disable runner auto-update

When the containers try to auto-update, they need to restart, which
cause them to come back on the old version. If the server instruct the
runner to update again, we can end up in continuously restarting the
runner without doing any meaningful work.

Our runners are being updated by a separate job [0] which produce a new
container nightly and eventually pick up the update, so we don't really
need the auto-update feature.

[0] https://github.com/kernel-patches/runner

Author: chantra

ansible/roles/runner/tasks/main.yml

@@ -95,6 +95,7 @@
       ORG_NAME={{ item.0.name }}
       {% endif %}
       RUNNER_NAME={{ runner_name_prefix }}-{{ 'worker-%02d' | format(item.1) }}
+      DISABLE_AUTO_UPDATE=true
   loop: "{{ runners | subelements('workers') }}"
 
 - name: Docker GHCR login