Add missing default Callables for new NavigationServer geometry parse and bake functions

Adds missing default Callables for new NavigationServer geometry parse and bake functions.

doc/classes/NavigationServer3D.xml

@@ -211,7 +211,7 @@
 			<return type="void" />
 			<param index="0" name="navigation_mesh" type="NavigationMesh" />
 			<param index="1" name="source_geometry_data" type="NavigationMeshSourceGeometryData3D" />
-			<param index="2" name="callback" type="Callable" />
+			<param index="2" name="callback" type="Callable" default="Callable()" />
 			<description>
 				Bakes the provided [param navigation_mesh] with the data from the provided [param source_geometry_data]. After the process is finished the optional [param callback] will be called.
 			</description>
@@ -681,7 +681,7 @@
 			<param index="0" name="navigation_mesh" type="NavigationMesh" />
 			<param index="1" name="source_geometry_data" type="NavigationMeshSourceGeometryData3D" />
 			<param index="2" name="root_node" type="Node" />
-			<param index="3" name="callback" type="Callable" />
+			<param index="3" name="callback" type="Callable" default="Callable()" />
 			<description>
 				Parses the [SceneTree] for source geometry according to the properties of [param navigation_mesh]. Updates the provided [param source_geometry_data] resource with the resulting data. The resource can then be used to bake a navigation mesh with [method bake_from_source_geometry_data]. After the process is finished the optional [param callback] will be called.
 				[b]Note:[/b] This function needs to run on the main thread or with a deferred call as the SceneTree is not thread-safe.

servers/navigation_server_3d.cpp

@@ -147,8 +147,8 @@ void NavigationServer3D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("obstacle_set_vertices", "obstacle", "vertices"), &NavigationServer3D::obstacle_set_vertices);
 	ClassDB::bind_method(D_METHOD("obstacle_set_avoidance_layers", "obstacle", "layers"), &NavigationServer3D::obstacle_set_avoidance_layers);
 
-	ClassDB::bind_method(D_METHOD("parse_source_geometry_data", "navigation_mesh", "source_geometry_data", "root_node", "callback"), &NavigationServer3D::parse_source_geometry_data);
-	ClassDB::bind_method(D_METHOD("bake_from_source_geometry_data", "navigation_mesh", "source_geometry_data", "callback"), &NavigationServer3D::bake_from_source_geometry_data);
+	ClassDB::bind_method(D_METHOD("parse_source_geometry_data", "navigation_mesh", "source_geometry_data", "root_node", "callback"), &NavigationServer3D::parse_source_geometry_data, DEFVAL(Callable()));
+	ClassDB::bind_method(D_METHOD("bake_from_source_geometry_data", "navigation_mesh", "source_geometry_data", "callback"), &NavigationServer3D::bake_from_source_geometry_data, DEFVAL(Callable()));
 
 	ClassDB::bind_method(D_METHOD("free_rid", "rid"), &NavigationServer3D::free);