Update phpstan/phpstan requirement from ^1.9 to ^1.9 || ^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@1.9.0...2.0.3)

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

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

composer.json

@@ -25,7 +25,7 @@
         "phpspec/prophecy-phpunit": "^2.0",
         "fakerphp/faker": "^1.19",
         "friendsofphp/php-cs-fixer": "^3.13",
-        "phpstan/phpstan": "^1.9"
+        "phpstan/phpstan": "^1.9 || ^2.0"
     },
     "autoload": {
         "psr-4": {