The directory /usr/etc is an optional directory and used by
Fedora, RHEL 9, and openSUSE. The purpose of /usr/etc is to store
distribution-provided configuration files that can be overridden
by user-modified files in /etc.

Also used in the sister project pyenv/pyenv#3039

Co-authored-by: Mislav Marohnić <git@mislav.net>