Add a feature spec for runner creation

What does this MR do and why?

Add a feature spec for runner creation

Screenshots or screen recordings

NA

How to set up and validate locally

1. Run $ bundle exec rspec spec/features/admin/admin_runners_spec.rb:494 in your installation

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 #383139 (closed)