Test: Update error message assertions for chunk update tests (#9468)

### What problem does this PR solve?

Modify test cases to accept additional error message format when
updating chunks.
fix actions:
https://github.com/infiniflow/ragflow/actions/runs/16942741621/job/48015850297

### Type of change

- [x] Update test cases

test/testcases/test_http_api/test_chunk_management_within_dataset/test_update_chunk.py

         delete_documents(HttpApiAuth, dataset_id, {"ids": [document_id]})
         res = update_chunk(HttpApiAuth, dataset_id, document_id, chunk_ids[0])
         assert res["code"] == 102
-        assert res["message"] == f"You don't own the document {document_id}."
+        assert res["message"] in [f"You don't own the document {document_id}.", f"Can't find this chunk {chunk_ids[0]}"]

test/testcases/test_sdk_api/test_chunk_management_within_dataset/test_update_chunk.py

 
         with pytest.raises(Exception) as excinfo:
             chunks[0].update({})
-        assert f"You don't own the document {chunks[0].document_id}" in str(excinfo.value), str(excinfo.value)
+        assert str(excinfo.value) in [f"You don't own the document {chunks[0].document_id}", f"Can't find this chunk {chunks[0].id}"], str(excinfo.value)