testing/lottie-qml: drop

The package that depended on it crashes because of it. Since it's not
strictly required for (bare minimum) functionality, let's just get rid
of it. Upstream of Plasma Mycroft knows about the issue and will work
towards using qt5-qtlottie instead
7 jobs for !8131 with testing_mycroft-gui in 17 seconds (queued for 2 seconds)
merge request