Fix CSGShape3D's _mesh_changed thread unsafe call to update_gizmos

modules/csg/csg_shape.cpp

@@ -934,7 +934,8 @@ CSGBrush *CSGMesh3D::_build_brush() {
 
 void CSGMesh3D::_mesh_changed() {
 	_make_dirty();
-	update_gizmos();
+
+	callable_mp((Node3D *)this, &Node3D::update_gizmos).call_deferred();
 }
 
 void CSGMesh3D::set_material(const Ref<Material> &p_material) {