Fix: some cases Task return but not set progress (#8469)

### What problem does this PR solve?
https://github.com/infiniflow/ragflow/issues/8466
I go through the codes, current logic:
When do_handle_task raises an exception, handle_task will set the
progress, but for some cases do_handle_task internal will just return
but not set the right progress, at this cases the redis stream will been
acked but the task is running.

### Type of change

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

---------

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

api/db/services/task_service.py

@@ -387,12 +387,12 @@ def queue_tasks(doc: dict, bucket: str, name: str, priority: int):
         for task in parse_task_array:
             ck_num += reuse_prev_task_chunks(task, prev_tasks, chunking_config)
         TaskService.filter_delete([Task.doc_id == doc["id"]])
-        chunk_ids = []
-        for task in prev_tasks:
-            if task["chunk_ids"]:
-                chunk_ids.extend(task["chunk_ids"].split())
-        if chunk_ids:
-            settings.docStoreConn.delete({"id": chunk_ids}, search.index_name(chunking_config["tenant_id"]),
+        pre_chunk_ids = []
+        for pre_task in prev_tasks:
+            if pre_task["chunk_ids"]:
+                pre_chunk_ids.extend(pre_task["chunk_ids"].split())
+        if pre_chunk_ids:
+            settings.docStoreConn.delete({"id": pre_chunk_ids}, search.index_name(chunking_config["tenant_id"]),
                                          chunking_config["kb_id"])
     DocumentService.update_by_id(doc["id"], {"chunk_num": ck_num})