Qt6.6 compatibility

src/AliasEditModel.cpp

src/Cache.cpp

src/ChatPage.cpp

src/InviteesModel.cpp

src/MxcImageProvider.cpp

src/PowerlevelsEditModels.cpp

src/UserSettingsPage.cpp

src/notifications/Manager.cpp

src/notifications/ManagerLinux.cpp

src/timeline/CommunitiesModel.cpp

src/timeline/DelegateChooser.cpp

src/timeline/EventDelegateChooser.cpp

src/timeline/EventStore.cpp

src/timeline/InputBar.cpp

src/timeline/RoomlistModel.cpp

src/ui/RoomSettings.cpp