no need of @ sybmol

.github/workflows/prerelease.yaml

@@ -581,7 +581,7 @@ jobs:
           git checkout test-preview-env
           git merge main -m "Merge with main"
 
-          sed -i 's/TEST:v.*/TEST:@${{ steps.tag_name.outputs.tag }}/g' porter.yaml
+          sed -i 's/TEST:v.*/TEST:${{ steps.tag_name.outputs.tag }}/g' porter.yaml
 
           git diff --quiet --exit-code || git add . && git commit -m "Update to Porter GHA version ${{steps.tag_name.outputs.tag}}" && git push -f
   run-new-release-tests-workflows: