replace wlsunset with gammastep

wlsunset doesn't work w/o manually passing the latitude and longitude.
gammastep can retrieve geolocation from geoclue so it works out of the
box for everyone.

.config/hypr/hyprland/execs.conf

@@ -1,5 +1,6 @@
 # Bar, wallpaper
 exec-once = swww-daemon --format xrgb
+exec-once = /usr/lib/geoclue-2.0/demos/agent
 exec-once = ags &
 
 # Input method
@@ -19,5 +20,3 @@ exec-once = wl-paste --type image --watch cliphist store
 
 # Cursor
 exec-once = hyprctl setcursor Bibata-Modern-Classic 24
-
-