Update dependency gitlab_quality-test_tooling to '~> 2.8.0'

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/177166



Merged-by: David Dieulivol <ddieulivol@gitlab.com>
Approved-by: Peter Leitzen <pleitzen@gitlab.com>
Co-authored-by: GitLab Renovate Bot <gitlab-bot@gitlab.com>