fix: conditional missing brackets

Author: jackhodgkiss

.github/workflows/stackhpc-container-image-build.yml

@@ -253,7 +253,7 @@ jobs:
               if docker push $image; then
                 echo "Pushed $image"
                 break
-              elif $i == 5; then
+              elif [ $i -eq 5 ] ; then
                 echo "Failed to push $image"
                 echo $image >> image-build-logs/push-failed-images.txt
               else