Add stale runners filters and badge

What does this MR do and why?

This change allows administration users to identify stale runners in their instance and filter them in the search.

❗ Depends on !74619 (merged), which should be in workflowproduction before merging this one.

Screenshots or screen recordings

Stale is now selectable

Stale runners are marked as such

How to set up and validate locally

1. Follow steps in this MR, to ensure at least one runner is stale (not connected in over 3 months): !74619 (merged)
2. Visit the runners admin page (logged in as admin): http://gdk.test:3000/admin/runners

MR acceptance checklist

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

• I have evaluated the MR acceptance checklist for this MR.

Related to #342799 (closed)