Rollback to node 14

Author: bidoubiwa

.github/workflows/tests.yml

@@ -56,7 +56,7 @@ jobs:
       - name: Setup node
         uses: actions/setup-node@v2
         with:
-          node-version: "16.x"
+          node-version: "14.x"
       - name: Install dependencies
         run: yarn --dev && yarn --cwd ./playgrounds/html
       - name: Browser tests