Remove invalid argument when writing to stream

The second argument of `stream.Writable.write()` is the encoding of the
chunk. Node 14 didn't seem to mind that it was set to `true`, which is
invalid, but Node 18 does and throws an error as a result.

lib/commands/implementations/mute.js

@@ -22,7 +22,6 @@ function mute(input, services) {
         parsedDuration,
         `Muting: ${userToPunish} for ${formatDuration(moment.duration(parsedDuration, 'seconds'))}`,
       ),
-      true,
     );
   });
   return new CommandOutput(null, null);

lib/commands/implementations/mutelinks.js

@@ -63,7 +63,6 @@ function mutelinks(defaultPunishmentDuration) {
           muteDuration,
           `${data.user} muted for ${formattedDuration} for posting a link while link muting is on.`,
         ),
-        true,
       );
     });
     const displayState = state === 'all' ? 'on for all links' : state;