This is basically a partial backport of commit b14e833ef6
("machine: add test to check config mount").
It seems on the ubuntu github actions runners we have XDG_CONFIG_HOME
set so the tests do not actually use its own private dir but a shared
one for the configs which breaks the test assumptions.
Signed-off-by: Paul Holzinger <pholzing@redhat.com>
e71ded2997