Improve container image tag file header comment

Author: Alex-Welsh

ansible/test-kayobe-repo-version-generate.yml

@@ -31,7 +31,9 @@
       copy:
         content: |
           ---
-          # Do not edit! This file is autogenerated by Ansible.
+          # This file is autogenerated by Ansible.
+          # To generate a new file with the latest versions, use this workflow:
+          # https://github.com/stackhpc/stackhpc-release-train/actions/workflows/package-update-kayobe.yml
           {{ updated_kayobe_pulp_repo_versions | to_nice_yaml }}
         dest: "{{ kayobe_pulp_repo_versions_dest }}"
         mode: 0755