Update walk-through.yaml --> fix error creating "{{base_folder}}"

[ibrahimlakkis]

the {{base_folder}} on {{ topology_file }} are not substituted with their value so it creates a {{base_folder}} on /tf/caf/landingzones/templates/ansible/{{base_folder}}

Issue-id

PR Checklist

---

• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My code follows the code style of this project.
• I ran lint checks locally prior to submission.
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Description

Does this introduce a breaking change

• YES
• NO

Testing