act_runner runs JS actions (checkout/cache) with node inside the job
container; rust:1-slim ships no node, so every JS action failed with
exit 127 ("node: not found"). Drop the container, run on the
node-equipped ubuntu-latest image, install Rust via rustup. The postgres
service is still reachable by name (act_runner containerises the job).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>