CI: disable registry caching (#30474)

* Revert "CI: separate image for docker cache (#30413)"

This reverts commit 361ffb5e54.

* Revert "CI: enable buildx for registry cache (#30473)"

This reverts commit edf90f3e76.

.github/workflows/setup/action.yaml

@@ -68,7 +68,8 @@ runs:
         find . -type f -executable -not -perm 755 -exec chmod 755 {} \;
         find . -type f -not -executable -not -perm 644 -exec chmod 644 {} \;
     - id: setup-buildx-action
-      name: setup docker buildx for registry cache
+      if: contains(runner.name, 'buildjet')
+      name: Set up Docker Buildx on buildjet to ensure a consistent cache
       uses: docker/setup-buildx-action@v2
       with:
         driver: docker-container