Update nikic/php-parser requirement from ^5.3 to ^5.6 (#158)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

composer.json

@@ -21,7 +21,7 @@
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^3.87",
-        "nikic/php-parser": "^5.3",
+        "nikic/php-parser": "^5.6",
         "phpstan/extension-installer": "^1.4",
         "phpstan/phpstan-deprecation-rules": "^2",
         "phpunit/phpunit": "^9 || ^10.5",