Install Rust with temporary Cargo and Rustup homes so cargo install can run cleanly in the container build.
- Added
CARGO_HOMEandRUSTUP_HOMEexports before the Rust toolchain install. - Switched from the distro
rustuppackage to the upstream installer. - Copied
wscfrom the temporary Cargo home instead of$HOME/.cargo. - Removed the temporary Cargo and Rustup directories after installation.
- This keeps the original compiler choice and version pin intact.