Update dependencies in composer.json and composer.lock

- Bump phpunit/phpunit from ^12.0 to ^12.5.8
- Update myclabs/deep-copy from 1.13.0 to 1.13.4
- Upgrade nikic/php-parser from v5.4.0 to v5.7.0
- Upgrade phpstan/phpstan from 2.1.11 to 2.1.38
- Upgrade phpunit/php-code-coverage from 12.1.0 to 12.5.3
- Update various references and URLs in composer.lock

These changes ensure compatibility with the latest versions of the dependencies.

Author: Florian Krämer

composer.json

@@ -3,7 +3,7 @@
     "type": "library",
     "require-dev": {
         "phpstan/phpstan": "^2.1",
-        "phpunit/phpunit": "^12.0",
+        "phpunit/phpunit": "^12.5.8",
         "squizlabs/php_codesniffer": "^3.12"
     },
     "autoload": {