text: Title: Rate-limited when using SlackAPIFileOperator with channel name
  Body: ### Apache Airflow version
  
  main (development)
  
  ### If "Other Airflow 2 version" selected, which one?
  
  2.10.4
  
  ### What happened?
  
  Reopening https://github.com/apache/airflow/issues/44923
  
  Per [Slack API rate limits](https://api.slack.com/apis/rate-limits), a `sleep(interval)` is needed in 
  https://github.com/apache/airflow/blob/1addb55154fbef31bfa021537cfbd4395696381c/providers/slack/src/airflow/providers/slack/hooks/slack.py#L188
  
  and `interval` should be an input argument, otherwise we can never use the friendly channel names and have to use the unreadable channel IDs
  
  ### What you think should happen instead?
  
  A configurable sleep should be used right after
  
  https://github.com/apache/airflow/blob/1addb55154fbef31bfa021537cfbd4395696381c/providers/slack/src/airflow/providers/slack/hooks/slack.py#L204
  
  to get around Slack's rate limits
  
  
  ### How to reproduce
  
  Use `SlackAPIFileOperator` with a channel name:
  
  ```python
  slack_operator_file_content = SlackAPIFileOperator(
      task_id="slack_file_upload",
      dag=dag,
      slack_conn_id="slack",
      channels="#general",
      initial_comment="Hello World!",
      content="file content in txt",
  )
  ```
  
  ### Operating System
  
  ubuntu debian
  
  ### Versions of Apache Airflow Providers
  
  All versions after 8.9.0+
  
  ### Deployment
  
  Other Docker-based deployment
  
  ### Deployment details
  
  _No response_
  
  ### Anything else?
  
  _No response_
  
  ### Are you willing to submit PR?
  
  - [x] Yes I am willing to submit a PR!
  
  ### Code of Conduct
  
  - [x] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)
  