arm64 based Docker image

[abigstupidbear]

Hello, could you provide an arm64 based Docker image? If possible, thank you very much！！！

[BWibo]

Hey there,

check this out: https://github.com/tum-gis/cesium-terrain-builder-docker/pkgs/container/ctb-quantized-mesh
I just added a multi-arch build workflow, that builds for amd64 and arm64 both debian and alpine image variants.

It would be cool if you could test both debian and alpine on arm64. I don't have an arm64 system at hand.

[BWibo]

@abigstupidbear Have you tried this out? Please report back if you did! Thx in advance.