Update phpstan/phpstan requirement from 2.1.38 to 2.1.40 (#116)

---
updated-dependencies:
- dependency-name: phpstan/phpstan
  dependency-version: 2.1.40
  dependency-type: direct:development
...

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

Author: dependabot[bot]

composer.json

@@ -19,7 +19,7 @@
   },
   "require-dev": {
     "phpunit/phpunit": "8.5.38",
-    "phpstan/phpstan": "2.1.38",
+    "phpstan/phpstan": "2.1.40",
     "squizlabs/php_codesniffer": "^4.0",
     "phpmd/phpmd": "^2.13",
     "guzzlehttp/guzzle": "^7.5"