The new task does a few things:
1. Having an extra build target makes the workflow file cleaner
2. it downloads the release targets which we want to build docker images for
3. it extracts the tar files into sub folders. We need to extract into sub folders to so that our image can fine the binaries. By providing `platform` to `docker buildx` the variable `TARGETPLATFORM` will be available when building the image. This variable is either `linux/amd64/`, `linux/arm64/` or `linux/arm/v7`. Hence we need to extract into subfolders.
4. We create 2 images, one for the maker and one for the taker. The images are then pushed to our organisation's docker registry.
Philipp Hoenisch
ae97873359