📦 Stick with working version of integration tests package

TO BE REVERTED after [1] AND need to update min version for the tests package

[1] php-http/client-integration-tests#60

Author: andrew-demb

composer.json

@@ -17,10 +17,11 @@
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^3.51",
-        "php-http/client-integration-tests": "^3.0",
+        "php-http/client-integration-tests": "3.0.1",
         "php-http/message": "^1.16",
         "php-http/client-common": "^2.7",
-        "phpunit/phpunit": "^8.5.23 || ~9.5"
+        "phpunit/phpunit": "^8.5.23 || ~9.5",
+        "php-http/message-factory": "^1.1"
     },
     "provide": {
         "php-http/client-implementation": "1.0",