update the major version

Author: shu-yusa

composer.json

@@ -5,7 +5,7 @@
   "keywords": ["rpc"],
   "homepage": "https://grpc.io",
   "license": "Apache-2.0",
-  "version": "1.57.0",
+  "version": "2.0.0",
   "require": {
     "php": "^8.1.0",
     "ext-grpc": "*"