docker buildx linux/arm64

[zhonghua-zheng]

I noticed linux/arm64 is not available at https://github.com/compdyn/partmc/blob/master/.github/workflows/images.yml. Can we add linux/arm64 to the platforms?

• https://github.com/compdyn/partmc/blob/master/.github/workflows/images.yml#L32
• https://github.com/compdyn/partmc/blob/master/.github/workflows/images.yml#L44