Fix nvidia flickering

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

hosts/eirene/hardware/default.nix

@@ -83,13 +83,22 @@
     {
       wayland.windowManager.hyprland.settings = {
         env = [ "AQ_DRM_DEVICES,$HOME/.config/hypr/card" ];
+
         device = [
           {
             name = "syna2ba6:00-06cb:ce44-touchpad";
             sensitivity = 0.5;
           }
         ];
+
         gestures.workspace_swipe_distance = 600;
+
+        # https://github.com/hyprwm/Hyprland/issues/6701
+        render = {
+          explicit_sync = 1;
+          explicit_sync_kms = 1;
+          direct_scanout = 0;
+        };
       };
 
       programs.zsh.loginExtra = lib.mkBefore (builtins.readFile ./card.sh);