Add feature tests and documentation to "show only inherited" runners (3)

What does this MR do and why?

Add feature tests to show all available runners for group owners. The feature was implemented in the previous MR at !97108 (merged), this adds some feature tests to it.

MR
Display shared runner details to group owners (1) (!99084 - merged)
Show all runners for group (2) (!97108 - merged)
Add feature tests and documentation to "show on... (!99087 - merged)	☝ you are here!

Screenshots or screen recordings

NA: These changes do not impact the UI.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

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 #337838 (closed)