fix(ci): fix tests rules

Author: pedrobrantes

.github/workflows/ci.yml

@@ -54,6 +54,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Download Docker image artifact
+        if: needs.build-docker-image.outputs.build_ran == 'true'
         uses: actions/download-artifact@v4
         with:
           name: nix-docker-image