Update phpstan/phpstan requirement from ^1.11.7 to ^1.11.8 (#651)

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](phpstan/phpstan@1.11.7...1.11.8)

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

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

composer.json

@@ -31,7 +31,7 @@
 		"friendsofphp/php-cs-fixer": "^3.59.3",
 		"php-coveralls/php-coveralls": "^2.7.0",
 		"phpstan/extension-installer": "^1.4.1",
-		"phpstan/phpstan": "^1.11.7",
+		"phpstan/phpstan": "^1.11.8",
 		"phpstan/phpstan-phpunit": "^1.4.0",
 		"phpstan/phpstan-strict-rules": "^1.6.0",
 		"phpunit/phpunit": "^9.6.20",