remove typecast to unknown

Somehow I thought it was necessary because the compiler said it at some point

server/commands/closepoll.ts

@@ -29,7 +29,7 @@ export default new Command({
 export async function closePoll(guild: Guild, requestId: string) {
     const guildId = guild.id
     logger.info("stopping poll", { guildId: guildId, requestId })
-    const channels: TextChannel[] = <TextChannel[]><unknown>(await guild.channels.fetch())
+    const channels: TextChannel[] = <TextChannel[]>(await guild.channels.fetch())
         ?.filter(channel => channel!.id === config.bot.announcement_channel_id)
         .map((value, _) => value)