Update Node.js to v16

Author: renovate-bot

.circleci/config.yml

@@ -16,7 +16,7 @@ jobs:
     # You can specify an image from Dockerhub or use one of our Convenience Images from CircleCI's Developer Hub.
     # A list of available CircleCI Docker Convenience Images are available here: https://circleci.com/developer/images/image/cimg/node
     docker:
-      - image: cimg/node:15.1
+      - image: cimg/node:16.8
     # Then run your tests!
     # CircleCI will report the results back to your VCS provider.
     steps:
@@ -40,7 +40,7 @@ jobs:
 
   build-and-test:
     docker:
-      - image: cimg/node:15.1
+      - image: cimg/node:16.8
     steps:
       - checkout
       - node/install-packages: