Don't setup DB for slack notification build

.gitlab-ci.yml

@@ -252,6 +252,9 @@ coverage:
 
 notify:slack:
   stage: post-test
+  variables:
+    USE_DB: "false"
+    USE_BUNDLE_INSTALL: "false"
   script:
     - ./scripts/notify_slack.sh "#builds" "Build on \`$CI_BUILD_REF_NAME\` failed! Commit \`$(git log -1 --oneline)\` See <https://gitlab.com/gitlab-org/$(basename "$PWD")/commit/"$CI_BUILD_REF"/builds>"
   when: on_failure