Fix final Python style issues in Docker integration test

- Remove unused json import
- Fix import sorting with ruff auto-fix
- All Clickzetta files now pass style checks

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

api/tests/integration_tests/vdb/clickzetta/test_docker_integration.py

@@ -3,11 +3,12 @@
 Test Clickzetta integration in Docker environment
 """
 import os
-import json
-import requests
 import time
+
+import requests
 from clickzetta import connect
 
+
 def test_clickzetta_connection():
     """Test direct connection to Clickzetta"""
     print("=== Testing direct Clickzetta connection ===")