docs(langgraph): update usage example to connector-based naming

Update the docstring usage example in langgraph.py to use
connector-based naming (hibob_*) and the current fetch_tools API
instead of the deprecated get_tools method with unified API naming.

Author: ryoppippi

stackone_ai/integrations/langgraph.py

@@ -7,7 +7,7 @@
     from stackone_ai.integrations.langgraph import to_tool_node
 
     toolset = StackOneToolSet()
-    tools = toolset.get_tools("hris_*", account_id="...")
+    tools = toolset.fetch_tools(actions=["hibob_*"], account_ids=["..."])
     node = to_tool_node(tools)  # langgraph.prebuilt.ToolNode
 """