Fix publish

Author: SamTV12345

.github/workflows/npmpublish.yml

@@ -17,6 +17,10 @@ jobs:
     if: ${{ github.event.workflow_run.conclusion == 'success' }}
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          registry-url: https://registry.npmjs.org/
       - name: Check out Etherpad core
         uses: actions/checkout@v3
         with: