Take test out of quarantine

What does this MR do and why?

I ran this test multiple times locally and I couldn't reproduce a long duration, it never takes longer than 300 ms.

$ yarn jest --no-cache spec/frontend/ci/runner/admin_runners/admin_runners_app_spec.js --verbose

shows total runner counts
      ✓ fetches counts (229 ms)
      ✓ shows the runner tabs (114 ms)
      ✓ shows the total (112 ms)

If I quarantine it back the same duration applies to the nearby tests, as the before block is still run:

shows total runner counts
      ✓ shows the runner tabs (257 ms)
      ✓ shows the total (126 ms)
      ○ skipped fetches counts

Taking this test out of quarantine.

Screenshots or screen recordings

NA

How to set up and validate locally

$ yarn jest --no-cache spec/frontend/ci/runner/admin_runners/admin_runners_app_spec.js --verbose

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 #414975 (closed)