feat: 1. replace black with ruff for fomatting and sort import (#489)

2. use tavily from`langchain-tavily` rather than the older one from `langchain-community`

Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

tests/unit/tools/test_crawl.py

@@ -1,9 +1,9 @@
 from unittest.mock import Mock, patch
+
 from src.tools.crawl import crawl_tool
 
 
 class TestCrawlTool:
-
     @patch("src.tools.crawl.Crawler")
     def test_crawl_tool_success(self, mock_crawler_class):
         # Arrange