Update Node.js to v16.8.0 (#403)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

Author: renovate[bot]

.circleci/config.yml

@@ -4,7 +4,7 @@ jobs:
 
   build:
     docker:
-      - image: circleci/node:16.5.0
+      - image: circleci/node:16.8.0
     steps:
       - checkout
       - restore_cache:
@@ -31,7 +31,7 @@ jobs:
 
   deploy-gh-pages:
     docker:
-      - image: circleci/node:16.5.0
+      - image: circleci/node:16.8.0
     steps:
       - checkout
       - run: