The function is hardcoding the provider name while there's a variable
for that. So use it.

Signed-off-by: Arnaud Patard <apatard@hupstream.com>

The machine status returned by vagrant may change between providers
so add code to deal with the differences. For now, it's coded inside
a function but can be replaced with a dict() if more differences are
found.

Signed-off-by: Arnaud Patard <apatard@hupstream.com>

Current provider is hardcoded inside the test file. We may want
to switch easily between test providers (local testing, using
something else than GHA, whatever...) so add a new function used
to return the current test provider.

Changing the test provider is done by setting an environment variable
since any code / logic to detect the provider to use will always
be broken.

Signed-off-by: Arnaud Patard <apatard@hupstream.com>