Resolve "Unable to start rails console if using master from gitlab-shell"

What does this MR do?

When running the rails console, handle case where the gitlab-shell is not available to provide version information.

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

See issue #46991 (closed)

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• [-] Changelog entry added, if necessary
• [-] Documentation created/updated
• [-] API support added
• [-] Tests added for this feature/bug
• Conform by the code review guidelines
  • [-] Has been reviewed by a UX Designer
  • [-] Has been reviewed by a Frontend maintainer
  • Has been reviewed by a Backend maintainer
  • [-] Has been reviewed by a Database specialist
• Conform by the merge request performance guides
• Conform by the style guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• [-] Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #46991 (closed)