c718f34d43
First, we now need the `vendor/` directory at the toplevel because that's where `Cargo.toml` is. Now this triggers another bug introduced in the build system with how we're handling the `rpmostree-rust.h` header. We ended up vendoring a pre-generated one in the tarball mainly because RHEL doesn't include cbindgen. Now probably in the future I'd like to fix that. But let's clean this up - the tarball generation process copies the file into `rpmostree-rust-prebuilt.h`, and build machinery detects that and entirely skips looking for or trying to build our internal cbindgen.