Remove redandent code. (#5121)

### What problem does this PR solve?

#5107

### Type of change

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

graphrag/general/community_reports_extractor.py

 import logging
 import json
 import re
-import traceback
 from typing import Callable
 from dataclasses import dataclass
 import networkx as nx
 from graphrag.general.extractor import Extractor
 from graphrag.general.leiden import add_community_info2graph
 from rag.llm.chat_model import Base as CompletionLLM
-from graphrag.utils import ErrorHandlerFn, perform_variable_replacements, dict_has_keys_with_types
+from graphrag.utils import perform_variable_replacements, dict_has_keys_with_types
 from rag.utils import num_tokens_from_string
 from timeit import default_timer as timer
 
 
     _extraction_prompt: str
     _output_formatter_prompt: str
-    _on_error: ErrorHandlerFn
     _max_report_length: int
 
     def __init__(
                         continue
                     response["weight"] = weight
                     response["entities"] = ents
-                except Exception as e:
+                except Exception:
                     logging.exception("CommunityReportsExtractor got exception")
-                    self._on_error(e, traceback.format_exc(), None)
                     continue
 
                 add_community_info2graph(graph, ents, response["title"])