Update phpstan/phpstan requirement from ^1.4 to ^1.4 || ^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@1.4.0...2.0.2)

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

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

composer.json

@@ -9,7 +9,7 @@
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^3.2",
         "jean85/composer-provided-replaced-stub-package": "^1.0",
-        "phpstan/phpstan": "^1.4",
+        "phpstan/phpstan": "^1.4 || ^2.0",
         "phpunit/phpunit": "^7.5|^8.5|^9.6",
         "vimeo/psalm": "^4.3 || ^5.0"
     },