Ensure that frontend fixtures job is run on forks

.gitlab/ci/rules.gitlab-ci.yml

@@ -1285,6 +1285,8 @@
     # From .frontend:rules:default-frontend-jobs
     - <<: *if-merge-request-labels-pipeline-expedite
       when: never
+    - <<: *if-fork-merge-request
+      changes: *code-backstage-patterns
     - if: '$ENABLE_RSPEC_FRONTEND_FIXTURE == "true"'
     - <<: *if-merge-request-labels-run-all-rspec
     # From .frontend:rules:jest