build(deps-dev): update phpstan/phpstan requirement || ^2.0

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/2.0.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@1.10.0...2.0.1)

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

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

composer.json

@@ -43,7 +43,7 @@
     "azuyalabs/php-cs-fixer-config": "^0.3",
     "mikey179/vfsstream": "^1.6",
     "phan/phan": "^5.4",
-    "phpstan/phpstan": "^1.10",
+    "phpstan/phpstan": "^1.10 || ^2.0",
     "phpunit/phpunit": "^8.5 || ^9.6",
     "vimeo/psalm": "^5.20"
   },