fix(example-todo-list): make foreign key optional in request body

Author: nabdelgadir

examples/todo-list/src/controllers/todo-list-todo.controller.ts

@@ -41,7 +41,10 @@ export class TodoListTodoController {
     @requestBody({
       content: {
         'application/json': {
-          schema: getModelSchemaRef(Todo, {exclude: ['id']}),
+          schema: getModelSchemaRef(Todo, {
+            exclude: ['id'],
+            optional: ['todoListId'],
+          }),
         },
       },
     })