testing/curaengine: upgrade to 4.9.1
This merge request upgrades CuraEngine and its dependency LibArcus to v4.9.1. Also, when would it be appropriate to move this package from the testing repository to the community repository?
This merge request upgrades CuraEngine and its dependency LibArcus to v4.9.1. Also, when would it be appropriate to move this package from the testing repository to the community repository?