[no ci] Downgrade to @actions/artifact@5.0.3

* update converted to esm modules, this breaks the script

Author: ChristopherHX

.github/workflows/update-repo.yml

@@ -331,7 +331,7 @@ jobs:
           GPG_PRIVATE_KEY: ${{ secrets.GPG_PRIVATE_KEY }}
 
       - name: install actions/artifact
-        run: npm install @actions/artifact
+        run: npm install @actions/artifact@5.0.3
 
       - name: create release index and sync packages
         uses: actions/github-script@v7
@@ -604,3 +604,4 @@ jobs:
         id: deployment
         uses: actions/deploy-pages@v4
 
+