Bump phpstan/phpstan from 1.9.8 to 1.9.9

Bumps [phpstan/phpstan](https://github.com/phpstan/phpstan) from 1.9.8 to 1.9.9.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Changelog](https://github.com/phpstan/phpstan/blob/1.10.x/CHANGELOG.md)
- [Commits](phpstan/phpstan@1.9.8...1.9.9)

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

composer.json

@@ -56,7 +56,7 @@
   "require-dev": {
     "phpunit/phpunit": "9.5.*",
     "squizlabs/php_codesniffer": "^3.7.1",
-    "phpstan/phpstan": "^1.9.8",
+    "phpstan/phpstan": "^1.9.9",
     "phpstan/phpstan-doctrine": "^1.3.31",
     "phpstan/phpstan-strict-rules": "^1.4.4",
     "phpstan/phpstan-phpunit": "^1.3.3",