scout: Add tests asserting that psmisc, python, python3 work
https://phabricator.collabora.com/T14616 and https://phabricator.collabora.com/T14627 ask for those two packages to be added to the spy SDK, so I added some very basic tests to assert that they work. We already have psmisc, python and python3 in the scout SDK, so we might as well run the same tests there.
Edited by Lucas Kanashiro