swh-lister v6.8.0 adds subvertpy in its requirements so libsvn-dev
must be installed or the wheel fails to build.

Also remove r-base-dev package which is no longer required since
the last changes introduced in the CRAN lister.

Refs. swh/infra/sysadm-environment#5398

Build the swh-graph-grpc-serve binary and only copy the result into the
destination image.

This splits the final image size to ~500Mo instead of ~1Go.

Refs. sysadm-environment#5382

Refs. sysadm-environment#5382