You might want to check ‘reusable workflows’ and update your blogpost :)
You can read about it in their blogpost of February 2022. It is now generally available.
To start, set up a workflow in one ‘main’ repo, and refer to it in the workflow files across multiple repositories:
jobs:
build:
uses:
my-organisation/my-awesome-main-repo/.github/workflows/myworkflow.yml@main
That’s basically it!