Nearly completely replace the original GitHub actions workflow.
Changes:
- Move from `.sh` files in `ci/steps` to steps in the workflow.
- Move from using docker images for environment to manual setup.
- Upgrade nfpm to v2.3.1
BREAKING CHANGE: official arm64 builds no longer support CentOS 7.
If you need to use CentOS 7 on arm64, build `code-server` locally.
For docs, see the yarn/npm section in `docs/install.md`.
I think at some point this script created the release and attached
assets but that's not the case anymore.
For some reason this would error with undefined variable reference for
joe but bash doesn't complain for me or Asher.
Not sure what the difference is.
