minetest-git is a Dockerfile to build a minetestserver from git. This conflicts zombi/minetest on Port 30000. If you want to run both, make sure to let one of it use a different port. It will also use a present default world at /data/minetest. The World might become uncompatible with older (stable) Versions of minetest.
Building and running minetest-git
docker compose up -d