build: 添加 Composer 中文网镜像

- 在 composer.json 文件中添加了 Composer 中文网镜像
- 新增镜像地址：https://packagist.phpcomposer.com
- 设置 canonical 为 false，保持官方镜像的优先级

composer.json

@@ -81,6 +81,12 @@
             "type": "composer",
             "url": "https://mirrors.aliyun.com/composer/",
             "canonical": false
+        },
+        {
+            "description": "Composer中文网镜像",
+            "type": "composer",
+            "url": "https://packagist.phpcomposer.com",
+            "canonical": false
         }
     ]
 }