fix(deps): update dependency symfony/mailer to v8

Author: renovate[bot]

composer.json

@@ -22,7 +22,7 @@
         "illuminate/http": "^10.0|^11.0|^12.0|^13.0",
         "illuminate/support": "^10.0|^11.0|^12.0|^13.0",
         "resend/resend-php": "^1.0.0",
-        "symfony/mailer": "^6.2|^7.0"
+        "symfony/mailer": "8.0.6"
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "^3.14",