feat: add Symfony 8 constraint for future compatibility

Prepare composer.json for Symfony 8 support by adding ^8.0 constraint
to symfony/finder, symfony/event-dispatcher, symfony/console, and
symfony/var-dumper dependencies.

Author: claude

composer.json

@@ -23,9 +23,9 @@
     ],
     "require": {
         "php": "^7.4|^8",
-        "symfony/finder": "^3.0|^4.0|^5.0|^6.0|^7.0",
-        "symfony/event-dispatcher": "^3.0|^4.0|^5.0|^6.0|^7.0",
-        "symfony/console": "^3.0|^4.0|^5.0|^6.0|^7.0",
+        "symfony/finder": "^3.0|^4.0|^5.0|^6.0|^7.0|^8.0",
+        "symfony/event-dispatcher": "^3.0|^4.0|^5.0|^6.0|^7.0|^8.0",
+        "symfony/console": "^3.0|^4.0|^5.0|^6.0|^7.0|^8.0",
         "symfony/polyfill-php80": "^1.20",
         "nikic/php-parser": "~5",
         "webmozart/assert": "^1.9",
@@ -40,7 +40,7 @@
         "phpspec/prophecy-phpunit": "^2.3",
         "phpunit/phpunit": "^7.5|^9.0|^10.0",
         "roave/security-advisories": "dev-master",
-        "symfony/var-dumper": "^3.0|^4.0|^5.0|^6.0|^7.0"
+        "symfony/var-dumper": "^3.0|^4.0|^5.0|^6.0|^7.0|^8.0"
     },
     "autoload": {
         "psr-4": {