[Contracts] add return types and bump to v3

Author: nicolas-grekas

composer.json

@@ -18,7 +18,7 @@
     "require": {
         "php": ">=8.0.2",
         "ext-amqp": "*",
-        "symfony/deprecation-contracts": "^2.1",
+        "symfony/deprecation-contracts": "^2.1|^3.0",
         "symfony/messenger": "^5.4|^6.0"
     },
     "require-dev": {