Update phpstan/phpstan requirement from 0.12.74 to 0.12.75

Updates the requirements on [phpstan/phpstan](https://github.com/phpstan/phpstan) to permit the latest version.
- [Release notes](https://github.com/phpstan/phpstan/releases)
- [Commits](phpstan/phpstan@0.12.74...0.12.75)

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

composer.json

@@ -9,7 +9,7 @@
         "pocketmine/log": "^0.2.0"
     },
     "require-dev": {
-        "phpstan/phpstan": "0.12.74",
+        "phpstan/phpstan": "0.12.75",
         "phpstan/extension-installer": "^1.0",
         "phpstan/phpstan-strict-rules": "^0.12.4"
     },