Update composer.json

remove unused dependency

Author: GeraudBourdin

composer.json

@@ -15,7 +15,6 @@
     },
     "require": {
         "symfony/http-client": "^6.4 || ^7.0",
-        "amphp/http-client": "^4.2.1",
         "knplabs/php-json-schema": "^0.1.0"
     }
 }