Set DPI scaling settings for GTK on Plasma/X11 sessions
GTK4 dropped support for the GDK_DPI_SCALE environment variable, but we can achieve the same using dedicated GTK/GDK settings. Here we drop any usage of environment variables for DPI configuration in favor of GTK/GDK settings.
BUG: 442901 FIXED-IN: 5.27
Edited by Fushan Wen