[ProcessPool] Remove useless comments when failed to delete the log f…

…iles (microsoft#3233)

# Description

Remove useless comments when failed to delete the log files

# All Promptflow Contribution checklist:
- [ ] **The pull request does not introduce [breaking changes].**
- [ ] **CHANGELOG is updated for new features, bug fixes or other
significant changes.**
- [ ] **I have read the [contribution guidelines](../CONTRIBUTING.md).**
- [ ] **Create an issue and link to the pull request to get dedicated
review from promptflow team. Learn more: [suggested
workflow](../CONTRIBUTING.md#suggested-workflow).**

## General Guidelines and Best Practices
- [ ] Title of the pull request is clear and informative.
- [ ] There are a small number of commits, each of which have an
informative message. This means that previously merged commits do not
appear in the history of the PR. For more information on cleaning up the
commits in your PR, [see this
page](https://github.com/Azure/azure-powershell/blob/master/documentation/development-docs/cleaning-up-commits.md).

### Testing Guidelines
- [ ] Pull request includes test coverage for the included changes.

src/promptflow-core/promptflow/executor/_line_execution_process_pool.py

@@ -461,8 +461,9 @@ def _monitor_workers_and_process_tasks_in_thread(
     def _delete_log_files(self):
         try:
             shutil.rmtree(ProcessPoolConstants.PROCESS_LOG_PATH)
-        except Exception as e:
-            bulk_logger.warning(f"Failed to delete the folder, exception: {e}")
+        except Exception:
+            # Ignore the exception when deleting the log files.
+            pass
 
     def _get_task_from_queue(self, task_queue: Queue):
         """Get task from the task queue. Ignore the queue being empty and only exit the loop when getting data."""