Recent(-ish) versions of Fedora have a drop-in configuration directory
for `sshd`. This allows applications, etc. to define certain settings
for the SSH server, without having to manage the entire server
configuration. For Gitea specifically, we only need to set a few
settings for the *gitea* user, leaving the remaining settings alone.
This commit does not include any migration to undo the settings that
were originally set, but that should be as simple as `mv
/etc/ssh/sshd_config.rpmnew /etc/ssh/sshd_config && systemctl reload
sshd`.
