chore: Pin node builder to 20 on the publish job

Author: kewisch

.github/workflows/publish.yaml

@@ -19,7 +19,7 @@ jobs:
       - name: "Setup Node"
         uses: actions/setup-node@v4
         with:
-          node-version: latest
+          node-version: 20
           registry-url: "https://registry.npmjs.org"
 
       - name: "npm ci"