Guild.bulk_ban optimization

[iyad-f]

Summary

This PR modifies Guild.bulk_ban to use the ban endpoint if the length of given users is 1.

Checklist

• If code changes were made then they have been tested.
  • I have updated the documentation to reflect the changes.
• 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, ...)

[iyad-f]

i type hinted user_ids with list[int, str] because otherwise http.bulk_ban wont accept it, maybe this is not the solution.

[Rapptz]

Believe it or not the endpoint itself already does this, kind of. When this was implemented on Discord's side they changed it so single ban is just a special case of bulk ban. There's no real benefit in doing this in the code, it's just an extra branch that the backend already does.

[iyad-f]

I see so there is no seperate strict rate limit for bulk-ban, is it calculated just with the normal ban endpoint?