Configure real git user

Create git user:

groupadd -g 1000 git
useradd -g git -u 1000 git -d "$(pwd)"/data/gitea/data/git
usermod -a -G docker git

/app/gitea/gitea: (chmod +x)

#!/bin/sh
docker exec -i -u git -e SSH_ORIGINAL_COMMAND="${SSH_ORIGINAL_COMMAND}" gitea-gitea $0 "$@"

/etc/ssh/sshd_config:

Match user git
  PasswordAuthentication no