rustbuilder

A base image for building Rust code, that should be less memory-intensive than using the default Rust images.

• based off official rust:slim-bookworm Docker image
• built for linux/arm64 and linux/amd64 platforms
• uses mold for linking
• makes Cargo use native git rather than libgit2, to workaround rust-lang/cargo#10583
• includes a prebuilt cargo-chef binary for cooking from recipe.json files

The build output target/ directory is /usr/local/build/target.