Exclude root socket from socket_user customfact chunk

[stdietrich]

If Podman user sockets have been enabled for root, calling facter -p podman in an interactive session as root will result into an error:

~# ll /run/user/0/podman/podman.sock
srw-rw---- 1 root root 0 Oct 20 22:19 /run/user/0/podman/podman.sock

~# facter -p podman
[2023-10-20 22:21:45.350548 ] ERROR Facter - Error while resolving custom fact fact='podman', resolution='<anonymous>': can't modify frozen String: "Cannot merge \"/run/podman/podman.sock\":String and \"/run/user/0/podman/podman.sock\":String"

This has been observed on Debian 11.8.

Excluding root from the socker_user chunk solves this issue and the fact works as expected, even for interactive logins of root:

~# facter -p podman
{
  socket => {
    Debian-gdm => "/run/user/118/podman/podman.sock",
    user => "/run/user/31257/podman/podman.sock",
    root => "/run/podman/podman.sock"
  },
  version => "3.0.1"
}

[southalc]

Thanks for submitting the bugfix!