Build packages for Centos 7

[bruno-at-orange]

For the fedora-like distro, we currently build and package khiops and kni on Rocky Linux 8 and 9. A user just asked kni for centos 7. it's neither urgent nor a priority because he build kni itself. But the question remains: should we package Khiops on centos 7 ? its end of life is Jun 30th, 2024.