/usr/share/doc/kwin-wayland-backend-wayland/changelog.Debian.gz is in kwin-wayland-backend-wayland 4:5.5.5-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/kwin-wayland-backend-wayland/../libkwinglutils7/changelog.Debian.gz