Improve Review Apps scheduled cleanup

By moving it to the `build` stage and adding `action: stop` to it.
Signed-off-by: Rémy Coutable <remy@rymai.me>

.gitlab/ci/review.gitlab-ci.yml

@@ -200,12 +200,11 @@ schedule:review-performance:
 schedule:review-cleanup:
   <<: *review-base
   <<: *review-schedules-only
-  stage: review
+  stage: build
   allow_failure: true
-  variables:
-    GIT_DEPTH: "1"
   environment:
     name: review/auto-cleanup
+    action: stop
   before_script:
     - source scripts/utils.sh
     - install_gitlab_gem