The `rust-ci.yml` build appears to be a bit flaky (we're looking into it...), so to save TypeScript contributors some noise, restrict the `rust-ci.yml` job so that it only runs on PRs that touch files in `codex-rs/`.
The `rust-ci.yml` build appears to be a bit flaky (we're looking into it...), so to save TypeScript contributors some noise, restrict the `rust-ci.yml` job so that it only runs on PRs that touch files in `codex-rs/`.