cmd-buildextend-metal: drop unused config parameters

These aren't used in the runvm-osbuild flow, but were for
create_disk.sh, which was dropped in d37958a.

Author: dustymabe

src/cmd-buildextend-metal

@@ -201,9 +201,6 @@ image_dynamic_yaml="${tmp_builddir}/image-dynamic.yaml"
 image_dynamic_json="${tmp_builddir}/image-dynamic.json"
 image_for_disk_json="${tmp_builddir}/image-for-disk.json"
 cat >"${image_dynamic_yaml}" << EOF
-buildid: "${build}"
-imgid: "${imgname}"
-ostree-commit: "${commit}"
 container-imgref: "${container_imgref}"
 deploy-via-container: "${deploy_via_container}"
 osname: "${name}"