Fix set_graph on non-existing edge (#6777)

### What problem does this PR solve?

Fix set_graph on non-existing edge

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

graphrag/general/index.py

@@ -72,12 +72,9 @@ async def run_graphrag(
     if not subgraph:
         return
 
-    graphrag_task_lock = RedisDistributedLock(f"graphrag_task_{kb_id}", lock_value=doc_id, timeout=3600)
-    while True:
-        if graphrag_task_lock.acquire():
-            break
-        callback(msg=f"merge_subgraph {doc_id} is waiting graphrag_task_lock")
-        await trio.sleep(20)
+    graphrag_task_lock = RedisDistributedLock(f"graphrag_task_{kb_id}", lock_value=doc_id, timeout=1200)
+    await graphrag_task_lock.spin_acquire()
+    callback(msg=f"run_graphrag {doc_id} graphrag_task_lock acquired")
 
     try:
         subgraph_nodes = set(subgraph.nodes())
@@ -95,6 +92,8 @@ async def run_graphrag(
             return
 
         if with_resolution:
+            await graphrag_task_lock.spin_acquire()
+            callback(msg=f"run_graphrag {doc_id} graphrag_task_lock acquired")
             await resolve_entities(
                 new_graph,
                 subgraph_nodes,
@@ -106,6 +105,8 @@ async def run_graphrag(
                 callback,
             )
         if with_community:
+            await graphrag_task_lock.spin_acquire()
+            callback(msg=f"run_graphrag {doc_id} graphrag_task_lock acquired")
             await extract_community(
                 new_graph,
                 tenant_id,