Code scanning default setup is now available for Go!
You can use default setup on your repository's "Settings" tab under "Code security and analysis".
This new feature is available on GitHub.com today, and will also ship with GHES 3.10. More language support will be provided soon, and all other CodeQL-supported languages continue to work using a GitHub Actions workflow file. The options to set up code scanning using API uploads or third party analysis tools remain supported and are unchanged.
For more information on code scanning default setup, see Configuring code scanning automatically.