os_images: rc assert bug fix

[bbezak]

TASK [stackhpc.openstack.os_images : Display warning message about the container engine] *************************************************************************************************************************************************************************************************************************************
task path: /home/rocky/deployment/src/openstack-config/ansible/collections/ansible_collections/stackhpc/openstack/roles/os_images/tasks/prechecks.yml:10
Wednesday 06 November 2024  11:09:52 +0100 (0:00:00.227)       0:00:08.409 ****
fatal: [localhost]: FAILED! =>
  msg: 'The conditional check ''result.rc = 0'' failed. The error was: template error while templating string: expected token ''end of statement block'', got ''=''. String: {% if result.rc = 0 %} True {% else %} False {% endif %}'