[cloudkitty] Another core team cleanup

Hello, Almost exactly two years since the last core team cleanup [1], it's probably time to have another one. I don't think we have heard from these contributors in the last couple of years: Justin Ferrieu jferrieu@objectif-libre.com Luis Ramirez luis.ramirez@opencloud.es Luka Peschke mail@lukapeschke.com Maxime Cottret maxime.cottret@gmail.com Stéphane Albert sheeprine@nullplace.com Jeremy Liu liuj285@chinaunicom.cn Is everyone okay with removing cloudkitty-core membership for these users? Cheers, Pierre Riteau (priteau) [1] https://lists.openstack.org/pipermail/openstack-discuss/2020-October/017751....