base-test: test new mirror-workspace role
This causes base-test to use the new mirror-workspace-git-repos role.
Once it lands, we can reparent jobs to base-test to evaluate it.
Depends-On:
- configure-unbound
- validate-host
- use-cached-repos
- - mirror-workspace-git-repos
+ - test-mirror-workspace-git-repos
- mirror-info
- configure-mirrors
- role: fetch-zuul-cloner
