ci: build the RISC-V binary

[come-maiz]

Part of #630.

📝 Summary

I've added the cross-build to RISC-V in the github workflow.

💡 Motivation and Context

I want us to make sure that all our sofware can run in RISC-V from the start. That will motivate others to do so, and by the time we have powerful RISC-V machines able to run rbuilder, we will be sooo ready.

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✅ I have completed the following steps:

• Run make lint
• Run make test
• Added tests (if applicable)

[come-maiz]

How can I test this?

[come-maiz]

I don't know what this is. The job runs in warp 24.04, right? What's this container for?

[sukoneck]

It's understandably confusing. I can add some comments for context to this.

We're running the jobs on Warpbuild runners whose pre-installed software are updated outside of our control by the Warpbuild team. So, to regain control over pre-installed software during the build we run the build inside of a container that runs on the Warpbuild runner.

    # defines the runner
    runs-on: warp-ubuntu-2404-x64-32x
    
    # the build is run inside of this container which is hosted on the runner
    container:
      image: ubuntu:22.04

[come-maiz]

mmm, so this will fail in a 22.04 container. I will try to run it in my fork as @metachris said.

[come-maiz]

this I also don't understand, what container?

[metachris]

@come-maiz you can fork the repo and test the release process there! just remove the warpbuild reference, which is just a faster runner but should use the same specs as the default runner.