Bump phpstan/phpstan from 2.0.3 to 2.1.0 in the dev-dependencies group

Bumps the dev-dependencies group with 1 update: [phpstan/phpstan](https://github.com/phpstan/phpstan).


Updates `phpstan/phpstan` from 2.0.3 to 2.1.0
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Changelog](https://github.com/phpstan/phpstan/blob/2.1.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@2.0.3...2.1.0)

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-type: direct:development
  update-type: version-update:semver-minor
  dependency-group: dev-dependencies
...

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

composer.json

@@ -7,7 +7,7 @@
         "glpi-project/tools": "^0.7",
         "php-parallel-lint/php-parallel-lint": "^1.4",
         "phpstan/extension-installer": "^1.4",
-        "phpstan/phpstan": "^2.0"
+        "phpstan/phpstan": "^2.1"
     },
     "config": {
         "optimize-autoloader": true,