add caching and use node16

.github/workflows/build.yml

@@ -31,7 +31,8 @@ jobs:
       - name: Install Node.js, NPM and Yarn
         uses: actions/setup-node@v2
         with:
-          node-version: 14
+          node-version: 16
+          cache: 'yarn'
 
        # Because of timeout issue https://github.com/yarnpkg/yarn/issues/4890
       - run: yarn install --network-timeout 1000000

.github/workflows/pr.yml

@@ -11,7 +11,8 @@ jobs:
 
       - uses: actions/setup-node@v2
         with:
-          node-version: 14
+          node-version: 16
+          cache: 'yarn'
 
       - run: yarn
       - run: npm run lint