Fix ruff lint: add blank line before class docstring

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: Maffooch

unittests/test_bulk_risk_acceptance_api.py

@@ -121,6 +121,7 @@ def test_finding_accept_risks(self):
 
 
 class TestBulkRiskAcceptanceRbac(APITestCase):
+
     """Tests that accept_risks endpoints use RBAC (Permissions.Risk_Acceptance) instead of is_staff."""
 
     @classmethod