Bump phpstan/phpstan from 0.12.88 to 0.12.89 (#4262)

Bumps [phpstan/phpstan](https://github.com/phpstan/phpstan) from 0.12.88 to 0.12.89.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Commits](https://github.com/phpstan/phpstan/compare/0.12.88...0.12.89)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

composer.json

@@ -38,7 +38,7 @@
       "pocketmine/spl": "^0.4.0"
    },
    "require-dev": {
-      "phpstan/phpstan": "0.12.88",
+      "phpstan/phpstan": "0.12.89",
       "phpstan/phpstan-phpunit": "^0.12.6",
       "phpstan/phpstan-strict-rules": "^0.12.2",
       "phpunit/phpunit": "^9.2"