In order to create the correct GLContext Krita has to create a
GLContext. This requires the QPA to be connected and a QGuiApplication.
However, this doesn't require loading styles and most importantly the
QPlatformTheme. Loading this multiple times within a process is somewhat
questionable and seems to cause issues with the Plasma QPT. Skipping it
should make things noticably faster too.
BUG: 408015