add .github/workflows/build.yml

[the-real-neil]

Looks like the SolidRun github remote isn't (yet) set up for github actions. Here's what this same commit does on my remote: https://github.com/rubicks/lx2160a_uefi/runs/3155559716

[jnettlet]

We do not use github actions for our CI builds. They are done through our own instance of drone.

[the-real-neil]

We do not use github actions for our CI builds. They are done through our own instance of drone.

Shucks; okay, thanks for letting me know.