feat: Add Guild.delete_auto_moderation_rule

[llamaair]

Summary

Add a function to delete auto moderation rules either by name or id.

Information

• This PR fixes an issue.
• This PR adds something new (e.g. new method or parameters).
• This PR is a breaking change (e.g. methods or parameters removed/renamed).
• This PR is not a code change (e.g. documentation, README, typehinting,
  examples, ...).

Checklist

• I have searched the open pull requests for duplicates.
• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• If type: ignore comments were used, a comment is also left explaining why.
• I have updated the changelog to include these changes.

[NeloBlivion]

Nowhere else in the library do we include a name kwarg for deletions (roles, emojis, guilds, channels etc.)... it shouldn't be included here either.
(We also already have AutoModRule.delete(), but having a method on guild is understandable to avoid an extra fetch.)

[llamaair]

Nowhere else in the library do we include a name kwarg for deletions (roles, emojis, guilds, channels etc.)... it shouldn't be included here either.

Ok, I'l remove the name kwarg 👍

[JustaSqu1d]

Maybe add AutoModRule.delete() as well?

Never mind that already exists

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