Update actions/upload-artifact action to v4

.forgejo/workflows/deploy.yaml

@@ -67,7 +67,7 @@ jobs:
         run: |
           rsync -v -r --delete -e "ssh -i deploykey.priv -o 'UserKnownHostsFile ./known_hosts'" public/ ht-ccchh-website-deploy@public-web-static-intern.hamburg.ccc.de:/var/www/hackertours.hamburg.ccc.de/
 
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         if: github.event_name == 'pull_request'
         with:
           name: website-build