/usr/lib/libgsf-gnome-1.so is in libgsf-gnome-1-dev 1.14.21-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libgsf-gnome-1.so.114.0.21
/usr/lib/libgsf-gnome-1.so.114.0.21