feat: update default attacker model suggestion

Author: vinceAmstoutz

vinceamstoutz/symfony-security-auditor/1.0/config/packages/symfony_security_auditor.yaml

@@ -4,7 +4,7 @@
 when@dev: &symfony_security_auditor
     symfony_security_auditor:
         model: 'claude-opus-4-8' # Model for both the Attacker and Reviewer roles. Bundle default: claude-opus-4-7.
-        # attacker_model: 'claude-opus-4-7' # Dedicated model for the Attacker role. Falls back to `model` when unset.
+        # attacker_model: 'claude-opus-4-8' # Dedicated model for the Attacker role. Falls back to `model` when unset.
         # reviewer_model: 'claude-haiku-4-5-20251001' # Lighter model for the Reviewer role. Falls back to `model` when unset.
 
 when@test: *symfony_security_auditor