[cicd][s]: Set up GitHub Actions

[sglavoie]

• Set up GitHub Actions to move away from GitLab CI.
• Create Action based on the following references:
  • Behavior desired from the old Playbook GitLab CI configuration: .gitlab-ci.yml.
  • File used as a reference to convert from GitLab CI to GitHub Actions: main.yml.
  • File on which this GitHub Action was based from an earlier setup with GitLab CI: .gitlab-ci.yml.

@cuducos if you could review this, it would be awesome! I tested it on a private repo on GitHub and it built successfully. However, another pair of eyes would be welcome :wink:.

I also switched from npm to yarn because I was facing different permission issues for some reason.