Rename graphrag task lock (#6576)

### What problem does this PR solve?

Rename graphrag task lock

### Type of change

- [x] Refactoring

graphrag/general/index.py

@@ -190,7 +190,7 @@ async def merge_subgraph(
     embedding_model,
     callback,
 ):
-    graphrag_task_lock = RedisDistributedLock("graphrag_task", lock_value=doc_id, timeout=600)
+    graphrag_task_lock = RedisDistributedLock(f"graphrag_task_{kb_id}", lock_value=doc_id, timeout=600)
     while True:
         if graphrag_task_lock.acquire():
             break
@@ -230,10 +230,11 @@ async def resolve_entities(
     embed_bdl,
     callback,
 ):
-    graphrag_task_lock = RedisDistributedLock("graphrag_task", lock_value=doc_id, timeout=600)
+    graphrag_task_lock = RedisDistributedLock(f"graphrag_task_{kb_id}", lock_value=doc_id, timeout=600)
     while True:
         if graphrag_task_lock.acquire():
             break
+        callback(msg=f"resolve_entities {doc_id} is waiting graphrag_task_lock")
         await trio.sleep(10)
 
     start = trio.current_time()
@@ -261,10 +262,11 @@ async def extract_community(
     embed_bdl,
     callback,
 ):
-    graphrag_task_lock = RedisDistributedLock("graphrag_task", lock_value=doc_id, timeout=600)
+    graphrag_task_lock = RedisDistributedLock(f"graphrag_task_{kb_id}", lock_value=doc_id, timeout=600)
     while True:
         if graphrag_task_lock.acquire():
             break
+        callback(msg=f"extract_community {doc_id} is waiting graphrag_task_lock")
         await trio.sleep(10)
 
     start = trio.current_time()