For some reason still not known, the `.git` directory was not copied
into the container. I think buildkit (buildx) did this by default before, and
stopped this with newer versions.
This PR fixes this by also touching `build.rs` besides `src/main.rs`.
This PR also updates Rust to v1.74.1 and some crates, including the
latest version of Alpine 3.19.
Fixes#4150