main: GDK_SCALE is read once

Both popups read it, each just before its own textinit, and the second
copy needed a comment to say why it was there at all.  One frontend runs
per session and popupscale is one global, so threadmain reads it before it
starts either -- which is before any setfont, the only ordering the two
copies were keeping.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

wl.c

@@ -647,7 +647,6 @@ void
 wlthread(void*)
 {
 	struct pollfd pfd;
-	char *scale;
 	int n;
 
 	threadsetname("wl");
@@ -657,11 +656,6 @@ wlthread(void*)
 		wllog("cannot make an xkb context");
 		return;
 	}
-	/* drawthread no longer runs, so the scale comes first: setfont
-	 * reads Fontsz. */
-	scale = getenv("GDK_SCALE");
-	if(scale != nil && atoi(scale) > 1)
-		popupscale = min(atoi(scale), 4);
 	textinit();
 	im = zwp_input_method_manager_v2_get_input_method(immgr, seat);
 	zwp_input_method_v2_add_listener(im, &imlisten, nil);