ci: update node version

Author: John60676

.github/workflows/codecov.yml

@@ -15,7 +15,7 @@ jobs:
       - name: setup node
         uses: actions/setup-node@v1
         with:
-          node-version: '12.x'
+          node-version: '16.x'
 
       - name: get yarn cache directory path
         id: yarn-cache-dir-path