I am wondering how I would configure a material in GoCD to trigger a build when a commit is made on the linked GitHub account.
You can follow "Integrating GoCD with GitHub" which uses a pull request workflow on GitHub side.
Each time a PR is done or updated on GitHub, the gocd-build-github-pull-requests plugin from Ashwanth Kumar would kick-in and build said PR, updating its status on GitHub after said build.