Move some vars to globals (#11017)

### What problem does this PR solve?

As title.

### Type of change

- [x] Refactoring

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

graphrag/light/smoke.py

@@ -28,6 +28,7 @@ from api.db.services.llm_service import LLMBundle
 from api.db.services.user_service import TenantService
 from graphrag.general.index import update_graph
 from graphrag.light.graph_extractor import GraphExtractor
+from common import globals
 
 settings.init_settings()
 
@@ -63,7 +64,7 @@ async def main():
 
     chunks = [
         d["content_with_weight"]
-        for d in settings.retriever.chunk_list(
+        for d in globals.retriever.chunk_list(
             args.doc_id,
             args.tenant_id,
             [kb_id],