refactor: remove obsolete builder methods

[almeidx]

Please describe the changes this PR makes and why it should be merged:

• Removed ApplicationCommandOptionChannelTypesMixin#addChannelType()
• Removed ApplicationCommandOptionWithChoicesAndAutocompleteMixin#addChoice()
• ApplicationCommandOptionChannelTypesMixin#addChannelTypes() only accepts rest parameters instead of an array

Status and versioning classification:

• Code changes have been tested against the Discord API, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating
• This PR changes the library's interface (methods or parameters added)
• This PR includes breaking changes (methods removed or renamed, parameters moved or removed)

[vvito7]

Shouldn't it also be changed in Slash Command Builders.md?

discord.js/packages/builders/docs/examples/Slash Command Builders.md

Lines 74 to 78 in 53defb8

	.addChoices([
	['Add points', 'add'],
	['Remove points', 'remove'],
	['Reset points', 'reset'],
	])

[vladfrangu]

I never liked this removal of singular vs multiple additions but 🤷 LGTM

[aedwardg]

Considering this message and the fact that builders 0.13.0 is required for upgrading to 13.7.0, it would have been nice if this breaking change were communicated better.