I've added licencing to the oxygen-sounds repo after discussion with Ruphy. I've removed the sounds from the oxygen repo and in Plasma 5.25 I'll release the oxygen-sounds repo.
https://invent.kde.org/plasma/oxygen/commit/3a99c77f70c3d2b211861b22ce7405e491c50804 https://invent.kde.org/plasma/oxygen-sounds/commit/e30bcb7680e5ef66e13e261061f4edbd71e6fc5a Jonathan
