also publish to ARM64

[agates4]

currently you publish images only as AMD64. we need ARM64

[allanger]

Hi, I've tried building an ARM image using cross-platform build, but it was taking hours to get finished. It should be possible to achieve by using arm runners, but I've never tried it before. I can have a look within a couple of weeks, but I also see that you've started working on it on your own. If you can come up with a PR, I would be happy to merge it