/usr/share/doc/python-libsss-nss-idmap/changelog.Debian.gz is in python-libsss-nss-idmap 1.16.1-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/python-libsss-nss-idmap/../libsss-nss-idmap0/changelog.Debian.gz