deps: update league/openapi-psr7-validator to 0.12

Author: canvural

composer.json

@@ -14,7 +14,7 @@
         "ext-json": "*",
         "cebe/php-openapi": "^1.4",
         "fzaninotto/faker": "^1.9",
-        "league/openapi-psr7-validator": "^0.11",
+        "league/openapi-psr7-validator": "^0.12",
         "thecodingmachine/safe": "^1.1"
     },
     "require-dev": {