T8073: Re-enable use of ln -r to drop delta from Debian

Previous versions or Aperits used an old coreutils-gplv2 which did not support ln -r. After switching to rust-coreutils, ln -r is available, which allows to drop this delta.

This also fixes issues with systems with not merged usr, like in LAVA NFS image.

Signed-off-by: Walter Lozano walter.lozano@collabora.com