Update nikic/php-parser requirement from ^5.3 to ^5.6

Updates the requirements on [nikic/php-parser](https://github.com/nikic/PHP-Parser) to permit the latest version.
- [Release notes](https://github.com/nikic/PHP-Parser/releases)
- [Changelog](https://github.com/nikic/PHP-Parser/blob/master/CHANGELOG.md)
- [Commits](nikic/PHP-Parser@v5.3.0...v5.6.1)

---
updated-dependencies:
- dependency-name: nikic/php-parser
  dependency-version: 5.6.1
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

composer.json

@@ -21,7 +21,7 @@
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^3.85",
-        "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",