feat: add support for ARM architecture

[reschandreas]

During my Artemis development I noticed that I could not create/manage any haskell exercises due to my computer's architecture. This PR adds a QEMU step and publishes images for amd and arm.

The QEMU build takes about 1h and 20 minutes

[b-fein]

Thanks for the contribution!

Only two formatting nitpicks, and one question. Otherwise looks good if the pipeline passes.

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Note to self: I’ll have to re-tag on main (or update to a newer Stack version here and in Artemis) to publish a new image that supports both architectures.

[reschandreas]

@b-fein thanks for approving, sometimes the pipeline fails because it takes too long and GitHub thinks it has lost connection. Just rerunning the job worked for me if I saw The hosted runner: GitHub Actions 2 lost communication with the server. Anything in your workflow that terminates the runner process, starves it for CPU/Memory, or blocks its network access can cause this error.

[reschandreas]

The action keeps failing because GitHub kills it, if GitHub would support ARM runners (or you have a self-hosted one), the arm image would build, just check my fork, it worked there.