Revert "Set GTK scaling env vars"

This reverts commit aba3d48c07.

It causes issues for multiple GTK apps when fractional factors are used.
Given GDK already has it's own auto scaling, this seems to cause more problems
than it solves in its current form.

BUG: 389523

startkde/startkde.cmake

@@ -49,7 +49,6 @@ kcminputrc Mouse cursorTheme 'breeze_cursors'
 kcminputrc Mouse cursorSize ''
 ksplashrc KSplash Theme Breeze
 ksplashrc KSplash Engine KSplashQML
-kdeglobals KScreen ScaleFactor ''
 kdeglobals KScreen ScreenScaleFactors ''
 kcmfonts General forceFontDPI 0
 EOF
@@ -95,8 +94,6 @@ fi
 
 if [ "$kdeglobals_kscreen_screenscalefactors" ]; then
     export QT_SCREEN_SCALE_FACTORS="$kdeglobals_kscreen_screenscalefactors"
-    export GDK_SCALE=$kdeglobals_kscreen_scalefactor
-    export GDK_DPI_SCALE=`echo "1 / $kdeglobals_kscreen_scalefactor" | bc -l`
 fi
 #Manually disable auto scaling because we are scaling above
 #otherwise apps that manually opt in for high DPI get auto scaled by the developer AND manually scaled by us