Skip review app on quarantine only changes

What does this MR do and why?

Checks if the changes in an MR only include (un)quarantined tests. If so, skip the review app to avoid wasting time/resources.

Closes https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1077

Test MRs and pipelines

• QA quarantine MR: !91963 (closed)
  • Skips Review App ✅ https://gitlab.com/gitlab-org/gitlab/-/pipelines/591989785
• QA change MR: !92850 (closed)
  • Runs Review App ✅ https://gitlab.com/gitlab-org/gitlab/-/pipelines/591997298

Non-QA change in this MR.

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.