Fix admin spec that flakes locally

What does this MR do and why?

When running this test locally, the test is flaky due to a field not being cleared correctly.

Screenshots or screen recordings

This shows how the expectation failed:

This MR aims to fix this.

How to set up and validate locally

Run the test locally:

$ bundle exec rspec spec/features/admin/admin_runners_spec.rb

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.