Fixup with the acutal option

Author: vmcj

.github/workflows/autoconf-check.yml

@@ -20,7 +20,7 @@ jobs:
           cd ..
           mv domjudge release
           tar -cf release.tar release
-          gzip -i release.tar
+          gzip -9 release.tar
       - name: Upload Artifact
         uses: actions/upload-artifact@v4
         with: