ci: add container builds for arm64

[manetherenio]

Description of changes:
This updates the Github Actions to add ARM64 builds. Currently, only AMD64 is being published to GHCR.

[github-actions]

Tests

Please note that running unit and e2e tests requires manual approval from a team member.

e2e tests

We use labels to control which e2e tests contexts are run:

Label	Behaviour
none	Run Generic tests only
e2e/none skip all e2e tests (documentation etc) - overrides all e2e/* labels	Do not run any e2e tests
e2e/flatcar run Flatcar e2e tests	Add Flatcar tests

ℹ️ Ask a team member to add the requested labels if you don't have enough permissions.

[mcbenjemaa]

Build is failing

[manetherenio]

It looks like buildx is currently incompatible with both --load and multiple simultaneous platform builds

docker/buildx#59 (comment)

How should we proceed? Remove the load line (currently here ) from the docker/build-push-action invocation?

Alternatively, I could setup a second docker/build-push-action invocation for arm64?

[manetherenio]

Reading further through the comment chain on the docker/buildx repo, it appears multi-arch builds and --load will work if using the containerd store. Let me try setting that up and see if that works.

[manetherenio]

So it looks like now with the containerd store enabled, the Trivy scanner is failing to load the new image locally. I'm going to build the arm64 container separately and use the amd64 container for the Trivy scanner.

[manetherenio]

@mcbenjemaa Builds are succeeding again. Can you please review?

[manetherenio]

@mcbenjemaa @wikkyk @LukasK32
Would someone be willing to give a review now that the builds are no longer failing?

[mcbenjemaa]

The build action is called twice.
Would it be possible to call it just once?

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[wikkyk]

This is definitely interesting. However, there are some major issues here:

1. No official support for arm64 in Proxmox VE
2. The arm64 builds would go completely untested.
3. I don't think it's enough to only scan the amd64 image with Trivy.

Is qemu necessary? Go cross-compiles well, there is no need to emulate an arm64. The only issue is tools like controller-gen that get installed at build time. I would rather make cross-compiling work properly (any build tools that are built at build time are built for host arch, everything else gets cross-compiled for target arch) so that e.g. I could do an arm64 build locally like make ARCH=arm64.

[ozhankaraman]

arm64 container images would be cool, I have an arm64 arch based Clusterapi management cluster and I am manually compiling capi-proxmox image