chore(ci): bump node version for release workflows

Author: stainless-app[bot]

.github/workflows/ci.yml

@@ -72,7 +72,7 @@ jobs:
       - name: Set up Node
         uses: actions/setup-node@v4
         with:
-          node-version: '18'
+          node-version: '20'
 
       - name: Bootstrap
         run: ./scripts/bootstrap

.github/workflows/publish-npm.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Set up Node
         uses: actions/setup-node@v3
         with:
-          node-version: '18'
+          node-version: '20'
 
       - name: Install dependencies
         run: |