/etc/fonts/conf.d/65-fonts-persian.conf is in fontconfig-config 2.9.0-7.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /etc/fonts/conf.d/../conf.avail/65-fonts-persian.conf
/etc/fonts/conf.d/../conf.avail/65-fonts-persian.conf