Add some required extensions in the composer.json

Author: stof

composer.json

@@ -22,6 +22,8 @@
     ],
     "require": {
         "php": "^7.1.3 || ^8.0",
+        "ext-dom": "*",
+        "ext-json": "*",
         "paragonie/random_compat": "^1 || ^2 || ^9",
         "symfony/config": "^4.4",
         "symfony/dependency-injection": "^4.4",