workflow: Bump nodejs to 20.x

Author: alcarney

.github/workflows/vscode-pr.yml

@@ -15,7 +15,7 @@ jobs:
 
     - uses: 'actions/setup-node@v4'
       with:
-        node-version: 18.x
+        node-version: 20.x
         cache: 'npm'
         cache-dependency-path: 'code/package-lock.json'