Handle non-versioned files in latest_version_file

### Description

For some reason SSB has decided to allow this.
If "v1" does not exist, we should fall back to looking for a non-versioned version.

<img width="197" height="144" alt="Image" src="https://github.com/user-attachments/assets/217a1895-11fb-4e39-83f7-e2449180026c" />