/usr/share/doc/libgtk2.0-dev/AUTHORS is in libgtk2.0-dev 2.24.23-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libgtk2.0-dev/../libgtk2.0-common/AUTHORS
/usr/share/doc/libgtk2.0-dev/../libgtk2.0-common/AUTHORS