CI: run build_docs_preview only with the label

tools/ci/config/deploy.yml

@@ -71,7 +71,7 @@ push_to_github:
 deploy_docs_preview:
   extends:
     - .deploy_docs_template
-    - .rules:labels:build_docs-slim
+    - .rules:labels:build_docs-preview
   # Override default stage to happen before the post_check
   stage: test_deploy
   needs:

tools/ci/config/rules.yml

@@ -134,6 +134,10 @@
     - <<: *if-protected-no_label
     - <<: *if-label-build_docs
 
+.rules:labels:build_docs-preview:
+  rules:
+    - <<: *if-label-build_docs
+
 .rules:labels:weekend_test-only:
   rules:
     - <<: *if-label-weekend_test