Allow symfony/console v6 (#56)

Author: BafS

composer.json

@@ -10,7 +10,7 @@
   "require": {
     "ext-json": "*",
     "flix-tech/avro-php": "^3.0|^4.0",
-    "symfony/console": "^4.3|^5.1",
+    "symfony/console": "^4.3|^5.1|^6.0",
     "nikic/php-parser": "^4.13",
     "pimple/pimple": "^3.5"
   },