chore: 简化结构化数据配置，移除不必要的嵌套

scripts/events/merge_config.js

@@ -567,9 +567,7 @@ hexo.extend.filter.register('before_generate', () => {
       enable: true,
       option: null
     },
-    structured_data: {
-      enable: true
-    },
+    structured_data: true,
     css_prefix: true,
     inject: {
       head: null,