Fixed signal connection examples to use new callable syntax in the docs

doc/classes/ConfirmationDialog.xml

@@ -8,10 +8,10 @@
 		To get cancel action, you can use:
 		[codeblocks]
 		[gdscript]
-		get_cancel().connect("pressed", self, "cancelled")
+		get_cancel_button().pressed.connect(self.cancelled)
 		[/gdscript]
 		[csharp]
-		GetCancel().Connect("pressed", this, nameof(Cancelled));
+		GetCancelButton().Pressed += Cancelled;
 		[/csharp]
 		[/codeblocks]
 	</description>