chore(deps): update dependency drupol/php-conventions to v6 (#50)

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

Author: renovate[bot]

composer.json

@@ -23,7 +23,7 @@
     },
     "require-dev": {
         "ext-pcov": "*",
-        "drupol/php-conventions": "^5",
+        "drupol/php-conventions": "^6",
         "friends-of-phpspec/phpspec-code-coverage": "^6",
         "infection/infection": "^0.27",
         "infection/phpspec-adapter": "^0.2.0",