Starting 0.31.0, all patch versions docker images (such as 0.31.1, 0.31.2 and so on) will be built only as RC (release candidate) and only for the AMD64 architecture.
All minor versions (0.32.0, 0.33.0 and so on) will be built for all supported architectures: AMD64, ARM64, ARM64v6, ARM64v7 and ARM64v8.
FYI