Fix mirroring repository settings stale tests

What does this MR do and why?

Fixes failures that interact with the

mirror_repository_url_field

selector, such as https://gitlab.com/gitlab-org/gitlab/-/jobs/4829456045 , MR that introduced the stale behaviour: !128167 (merged)

Related: #421412 (closed), #421411 (closed), #421413 (closed)

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