Incorrect Option Serialization Type

[IanMitchell]

Per Vlad and ckohen, the serialization should be typed like this:

Exclude<RESTPostAPIChatInputApplicationCommandsJSONBody["options"], undefined>[number]

[IanMitchell]

When updating, we should change the following code style:

		if (this.channelTypes != null) {
			payload.channel_types = this.channelTypes;
		}

We want to allow null and undefined values in, so we should just write the value to the payload itself to avoid bugs.