Promote php-http/message-factory to required dependency

Author: zanbaldwin

composer.json

@@ -17,12 +17,12 @@
         "php-http/discovery": "^1.0",
         "psr/http-client-implementation": "^1.0",
         "php-http/client-common": "^1.9 || ^2.0",
+        "php-http/message-factory": "^1.1",
         "composer-runtime-api": "^2.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^8.0 || ^9.0",
         "guzzlehttp/guzzle": "^7",
-        "php-http/message-factory": "^1.1",
         "php-http/mock-client": "^1.0",
         "friendsofphp/php-cs-fixer": "^3.0",
         "phpstan/phpstan": "^1.2"