ci: Run `gitlab:setup` when seed task files are changed

What does this MR do and why?

We had a broken master at gitlab-org/quality/engineering-productivity/master-broken-incidents#3373 (closed) where gitlab:setup didn't run when ee/lib/tasks/gitlab/seed/insights.rake was changed.

Fixes gitlab-org/quality/engineering-productivity/team#275 (closed).

MR acceptance checklist

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