To cross-build on x86_64, following QEMU packages are required:
sudo apt-get install -y gcc-arm-linux-gnueabihf libc6-dev-armhf-cross qemu-user-static qemu-system-i386
Then you can simply run this to re-build the binaries:
make all
Note
The following files are used by older versions of LocalStack where the download URL is hardcoded. Removing them will break these releases.