csharp: Do not use the System Bus for testing.
Summary: To allow the C# bindings running on the CI
Reviewers: zmike, brunobelo, felipealmeida, segfaultxavi, stefan_schmidt
Reviewed By: stefan_schmidt
Subscribers: cedric, reviewers, committers
Tags: efl
Maniphest Tasks: T8313
Differential Revision: https://phab.enlightenment.org/D10283