MINOR: remove old comment in streams StateDirectory (#18546)

Reviewers: Bruno Cadonna <cadonna@apache.org>, Chia-Ping Tsai <chia7712@gmail.com>

Author: aliehsaeedii

streams/src/main/java/org/apache/kafka/streams/processor/internals/StateDirectory.java

@@ -482,7 +482,6 @@ synchronized boolean lock(final TaskId taskId) {
             throw new IllegalStateException("The state directory has been deleted");
         } else {
             lockedTasksToOwner.put(taskId, Thread.currentThread());
-            // make sure the task directory actually exists, and create it if not
             return true;
         }
     }