fix(deps): update dependency psr/http-message to v2 (#72)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Diff for: providers/Flagd/composer.json

@@ -26,7 +26,7 @@
     "php-http/httplug": "^2.3.0",
     "psr/http-client": "^1.0",
     "psr/http-factory": "^1.0",
-    "psr/http-message": "^1.0",
+    "psr/http-message": "^2.0",
     "psr/log": "^2.0 || ^3.0"
   },
   "require-dev": {