[15.8 Backport] Fix suggested_reviewers runs when rails is disabled

What does this MR do and why?

Fixed the suggested reviewers recipe running even when rails is disabled. This causes crashes during reconfigure and package upgrade, because of missing directories. This is a backport of !6767 (merged) to 15.8.

Relates #7479 (closed)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• This MR is backporting a bug fix, documentation update, or spec fix, previously merged in the default branch.
  • Original MR: !6767 (merged)
• The original MR has been deployed to GitLab.com (not applicable for documentation or spec changes).
  • The original MR is in workflowproduction
• This MR has a severity label assigned (if applicable).
  • severity2

Note to the merge request author and maintainer

The process of backporting bug fixes into stable branches is tracked as part of an internal pilot. If you have questions about this process, please:

• Refer to the internal pilot issue for feedback or questions.
• Refer to the patch release runbook for engineers and maintainers for guidance.