[packit] 0.17.18 upstream release
    
    Upstream tag: 0.17.18
    Upstream commit: a1f42d21
    
    If you need to do any change in this pull request, you need to locally fetch the source branch of it and push it (with a fix) to your fork (as it is not possible to push to the branch created in the Packit’s fork):
    ```
    git fetch https://src.fedoraproject.org/forks/packit/rpms/umockdev.git refs/heads/*:refs/remotes/packit/*
    git checkout packit/0.17.18-rawhide-update-propose_downstream
    ```