Add ext-json to require-dev in composer.json

Author: koriym

composer.json

@@ -20,7 +20,8 @@
     "require-dev": {
         "ext-pdo": "*",
         "phpunit/phpunit": "^8.5.40 || ^9.5",
-        "bamarni/composer-bin-plugin": "^1.4"
+        "bamarni/composer-bin-plugin": "^1.4",
+        "ext-json": "*"
     },
     "config": {
         "sort-packages": true,