Fix channel checks missing GuildNews

The log channel / logclean checks are left as-is; hopefully nobody is
using an announcements channel for their logs?

PluralKit.Bot/Handlers/MessageEdited.cs

@@ -52,7 +52,7 @@ namespace PluralKit.Bot
                 return;
             
             var channel = _cache.GetChannel(evt.ChannelId);
-            if (channel.Type != Channel.ChannelType.GuildText)
+            if (DiscordUtils.IsValidGuildChannel(channel))
                 return;
             var guild = _cache.GetGuild(channel.GuildId!.Value);
             var lastMessage = _lastMessageCache.GetLastMessage(evt.ChannelId);