chore: Update Composer dev dependencies to v8

Author: renovate[bot]

composer.json

@@ -54,8 +54,8 @@
         "phpstan/phpstan-phpunit": "^2.0.8",
         "phpunit/phpunit": "^10.5.59",
         "rector/rector": "^2.2.11",
-        "symfony/cache": "^6.4||^7.0",
-        "symfony/var-exporter": "^6.4||^7.0"
+        "symfony/cache": "8.0.1",
+        "symfony/var-exporter": "8.0.0"
     },
     "suggest": {
         "php": "^8.4",