fix: use node 16 for bundle size action (#920)

node 16 is now supported in gh actions.

Ref: actions/runner#1439

Author: achingbrain

actions/bundle-size/.dockerignore

@@ -8,9 +8,5 @@ inputs:
     description: A directory to run the bundle check in
     required: false
 runs:
-  # TODO: we need node14.14 minimum.
-  # https://github.com/actions/runner/issues/772
-  # using: 'node12'
-  # main: 'dist/index.js'
-  using: 'docker'
-  image: 'Dockerfile'
+  using: 'node16'
+  main: 'dist/index.js'