Hotfix ece5903 (#6705)

I'm really sorry, I found that in graphrag/general/extractor.py under
def __call__, the line change.removed_nodes.extend(nodes[1:]) causes an
AttributeError: 'set' object has no attribute 'extend'. Could you please
merge the branch e666528 again? I made some modifications.

graphrag/general/extractor.py

@@ -193,7 +193,7 @@ class Extractor:
         if len(nodes) <= 1:
             return
         change.added_updated_nodes.add(nodes[0])
-        change.removed_nodes.extend(nodes[1:])
+        change.removed_nodes.update(nodes[1:])
         nodes_set = set(nodes)
         node0_attrs = graph.nodes[nodes[0]]
         node0_neighbors = set(graph.neighbors(nodes[0]))