Please do not use DISPLAY env variable to detect we are in graphical session

Hello

Now that wayland exists and that the installer will get wayland support when switching to GTK3 it's probably interesting to not rely on the DISPLAY environment variable (which is X11 specific)

An other way should be found for this

The issue points to the installer’s use of the DISPLAY environment variable and notes future GTK3 and Wayland support, but names no files or tests. Locate the graphical-session detection entry point, research a Wayland-compatible alternative, and verify that detection works without relying on DISPLAY.

Written by the indexing model from the issue text.