# 0.6.4
ci: build amd64/arm64 natively in parallel

Previously the workflow used qemu to build the arm64 image on the amd64
runner, which made each release take ~50min. Split into a matrix that
builds each arch on a native runner (ubuntu-latest for amd64,
ubuntu-24.04-arm for arm64), pushes each image by digest, then merges
them into a multi-arch manifest in a final job. Adds a per-platform GHA
buildx cache so subsequent runs with unchanged deps skip the cold cargo
build. Drops Swatinem/rust-cache (no effect inside Docker).
