No e2e test covering the single-node tutorial

[Nobuto Murata]

In the single-node tutorial:
https://microstack.run/docs/single-node

There are basically 6 main steps to complete it.

1. sudo snap install openstack --channel 2024.1/edge
2. sunbeam prepare-node-script | bash -x && newgrp snap_daemon
3. sunbeam cluster bootstrap --accept-defaults
4. sunbeam configure --accept-defaults --openrc demo-openrc
5. sunbeam launch ubuntu --name test
6. Access instance with `ssh -i /home/ubuntu/.config/openstack/sunbeam ubuntu@10.20.20.200`

However, by looking into the current definition of functional tests, the point 6 may not be covered yet.

ref: https://bugs.launchpad.net/snap-openstack/+bug/2067623

[Nobuto Murata (nobuto)]

https://github.com/canonical/snap-openstack/pull/240