ci: use newer node version for release

Author: felixfbecker

.github/workflows/build.yml

@@ -59,7 +59,7 @@ jobs:
       - name: Setup Node.js
         uses: actions/setup-node@v1
         with:
-          node-version: '6.17.1'
+          node-version: '14.15.3'
       - name: Install npm
         run: npm install -g npm@^6.3.0
       - name: Install npm dependencies