Bot.logout was deprecated

[InterStella0]

Rationale

After discord.py 1.7 update, Bot.logout was deprecated. This warning keeps popping up.

C:\Users\sarah\AppData\Local\Programs\Python\Python39-32\lib\site-packages\discord\ext\commands\core.py:85: 
 DeprecationWarning: logout is deprecated, use Client.close instead.
    ret = await coro(*args, **kwargs)

Summary of changes made

jsk_shutdown was using bot.logout so I changed it to bot.close

Checklist

• [x] This PR changes the jishaku module/cog codebase
  • [ ] These changes add new functionality to the module/cog
  • [x] These changes fix an issue or bug in the module/cog
  • [x] I have tested that these changes work on a production bot codebase
  • [ ] I have tested these changes against the CI/CD test suite
  • [ ] I have updated the documentation to reflect these changes
• [ ] This PR changes the CI/CD test suite
  • [ ] I have tested my suite changes are well-formed (all tests can be discovered)
  • [ ] These changes adjust existing test cases
  • [ ] These changes add new test cases
• [ ] This PR changes prose (such as the documentation, README or other Markdown/RST documents)
  • [ ] I have proofread my changes for grammar and spelling issues
  • [ ] I have tested that any changes regarding Markdown/RST syntax result in a well formed document

[scarletcafe]

CI is failing but this is due to the change in version locking in d.py 2.0