It's been replaced by cargo-deny in all modules.
Don't regenerate images for now, it's not a problem to keep it around
until the next images update round.
CARGO_HOME's semantic depends on when it's used in the pipeline:
- it's the install prefix when installing Cargo
- it's the crate cache location when building jobs
env.sh is sourced at the start of all jobs and was overidding the
CARGO_HOME path defined in the CI template for caching. Fix this by
moving the prefix install path to install-rust.sh.
