Disallow Adwaita themes on Wayland

[askmeaboutlo0m]

Fedora ships with a bunch of unmaintained Adwaita Qt styles, which have busted submenus on Wayland: FedoraQt/adwaita-qt#200

We should disable these under Wayland. The Adwaita style has the following entries (although I'd hope we can figure this out from something else than the names): HighContrastInverse, HighContrast, Adwaita-HighContrastInverse, Adwaita-HighContrast, Adwaita-Dark, Adwaita.

Credit Kawaxte for reporting.

[ghost]

As an alternative, could we perhaps look into Kvantum?

[askmeaboutlo0m]

As far as I can tell from their documentation, there's nothing to do, it should already be supported. You install Kvantum and Drawpile should pick up its Qt style plugin, just like any other.

Edit: yup.