ref: Fix some ruff rules for private access (SLF) (#4139)

* Add ruff rules for private access (SLF)

* Changes following review

* Rename Vertex._data to Vertex.full_data

src/backend/tests/integration/utils.py

@@ -169,4 +169,4 @@ async def run_single_component(
     _, _ = await run_graph_internal(
         graph, flow_id, session_id=session_id, inputs=graph_run_inputs, outputs=[component_id]
     )
-    return graph.get_vertex(component_id)._built_object
+    return graph.get_vertex(component_id).built_object