I moved my blog from WordPress to GitLab Pages in... 2016. I'm happy with the solution. However, I used GitHub Pages when I was teaching for both the courses and the exercises, e.g., Java EE. At the time, there was no GitHub Actions: I used Travis CI to build and deploy.
Recently, I had to use GitHub Pages to publish my Apache APISIX workshop. Travis is no longer free. GitHub Actions are a thing. I used the now nominal path and faced a few hurdles; here are my findings.