test: fix tests with newer dbusmock versions

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (e9a6ac2) 95.72% compared to head (1c31c88) 95.72%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #471 +/- ## ======================================= Coverage 95.72% 95.72% ======================================= Files 20 20 Lines 1333 1333 Branches 199 199 ======================================= Hits 1276 1276 Misses 46 46 Partials 11 11 ```

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:tada: This PR is included in version 6.1.0 :tada:

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