Look into / fixup build.yml Action warning about Node.js

[jimsmart]

When build.yml runs, it emits the following warning...

Node.js 12 actions are deprecated. For more information see: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/. Please update the following actions to use Node.js 16: actions/checkout@v2, actions/setup-go@v2