build: fix the build with dune 3.0

dune-project

-(lang dune 1.11)
+(lang dune 3.0)

tools/daemongui/gui.ml

@@ -81,7 +81,7 @@ let rdbg_get (cmd: string): string =
   | None -> assert false
 
 (** Compte le nombre de noeuds *)
-let rdbg_count_nodes (): int =
+let _rdbg_count_nodes (): int =
   let cmd = " List.length (List.filter (fun (n,v) -> String.length n > 5 && String.sub n 0 5 = \"Enab_\") !e.outputs);;" in
   let res = rdbg_get cmd in
   (* rdbg renvoie une réponse qui ressemble à "- : int = 7" *)
@@ -186,8 +186,8 @@ let update_rdbg_hook node activate =
   ()
 
 (* GTK3 *)
-let locale = GtkMain.Main.init ()
-let thread = GtkThread.start()
+let _locale = GtkMain.Main.init ()
+let _thread = GtkThread.start()
 let main () =
   let window = GWindow.window ~width:320 ~height:240
                               ~title:"Daemon GUI"

tools/gg/graphGen.ml

@@ -7,13 +7,13 @@ open UdgUtils
 open Sasacore
 
 
-exception Incorrect_attribute
+(* exception Incorrect_attribute *)
 
 let min_max = ref None
 let connected = ref None
 let cyclic = ref None
 let tree = ref None
-let height:int option ref = ref None
+(* let height:int option ref = ref None *)
 
 let generate_du_dur graph plan_udg t : unit =
   if (t.dotUDG <> "") then (