build(deps-dev): update phpstan/phpstan requirement

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/1.10.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@1.9.14...1.10.9)

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

Signed-off-by: dependabot[bot] <support@github.com>

composer.json

@@ -35,7 +35,7 @@
 		"marc-mabe/php-enum": "~4.6",
 		"mockery/mockery": ">=1.5.1",
 		"phpstan/extension-installer": "1.2.0",
-		"phpstan/phpstan": "1.9.14",
+		"phpstan/phpstan": "1.10.9",
 		"phpstan/phpstan-deprecation-rules": "1.1.1",
 		"phpstan/phpstan-nette": "1.2.3",
 		"phpstan/phpstan-mockery": "1.1.0",