Fix scalable test to check breeze for breeze-dark
Fix scalable test to check breeze for breeze-dark

As breeze-dark now inherits breeze theme, we also need to include
it when ensuring scalable versions of icons are available when
using the theme.

KDE/breeze-icons,KDE/breeze-icons,KDE/breeze-icons,KDE/breeze-icons,KDE/breeze-icons