fix: cp for main only

.ci-scripts/update-artifacts.sh

@@ -20,6 +20,8 @@ unzip -u old-artifact.zip
 # https://subugoe.pages.gwdg.de/ahiqar/website/${CI_COMMIT_REF_SLUG}/.
 # this has to be considered in the directory structure.
 
-cp --recursive public/main/* public/
+if [[ ${CI_COMMIT_REF_SLUG} == "main" ]]; then
+  cp --recursive public/main/* public/
+fi
 
-[ $? -eq 0 ] && exit 0
+# [ $? -eq 0 ] && exit 0