Typings: VoiceConnection.dispatcher has wrong type

[lasa01]

Please describe the problem you are having in as much detail as possible:
The TypeScript type definitions have incorrect type for VoiceConnection.dispatcher. In the documentation, the type is ?StreamDispatcher (nullable) while in the type definitons it is defined as StreamDispatcher (can't be null). When the bot is connected into a voice channel, but is not playing anything, the VoiceConnection.dispatcher is null.

Include a reproducible code sample here, if possible:

const discord = require("discord.js");
const client = new discord.Client();
await client.login(token);
const guild = client.guilds.cache.first();
const voiceChannel = guild.channels.cache.find((channel) => channel.type === "voice");
const connection = await voiceChannel.join();
connection.dispatcher === null

Further details:

• discord.js version: 12.5.1
• Node.js version: 14.15.0
• Operating system: Windows
• Priority this issue should have – please be realistic and elaborate if possible: not critical, but it's easy to fix

Relevant client options:

• partials: none
• gateway intents: none
• other: none

• I have also tested the issue on latest master, commit hash: c4c8171