[TASK] Update phpstan/phpstan requirement from ^1.11.8 to ^1.11.9 (#1424)

Updates the requirements on [phpstan/phpstan](https://github.com/phpstan/phpstan) to permit the latest version.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Changelog](https://github.com/phpstan/phpstan/blob/1.12.x/CHANGELOG.md)
- [Commits](https://github.com/phpstan/phpstan/compare/1.11.8...1.11.9)

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-type: direct:development
...

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

composer.json

@@ -55,7 +55,7 @@
 		"php-parallel-lint/php-parallel-lint": "^1.4",
 		"phpmd/phpmd": "^2.15.0",
 		"phpstan/extension-installer": "^1.4.1",
-		"phpstan/phpstan": "^1.11.8",
+		"phpstan/phpstan": "^1.11.9",
 		"phpstan/phpstan-phpunit": "^1.4.0",
 		"phpstan/phpstan-strict-rules": "^1.6.0",
 		"phpunit/phpunit": "^9.6.20",