/etc/fonts/conf.d/20-unhint-small-dejavu-serif.conf is in fonts-dejavu-core 2.37-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /etc/fonts/conf.d/../conf.avail/20-unhint-small-dejavu-serif.conf
/etc/fonts/conf.d/../conf.avail/20-unhint-small-dejavu-serif.conf