Update phpstan/phpstan requirement from ^0.12.23 to ^0.12.25

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@0.12.23...0.12.25)

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

composer.json

@@ -27,7 +27,7 @@
         "phpunit/phpunit": "^8.5",
         "psr/http-factory": "^1.0",
         "squizlabs/php_codesniffer": "^3.5",
-        "phpstan/phpstan": "^0.12.23"
+        "phpstan/phpstan": "^0.12.25"
     },
     "autoload": {
         "psr-4": {