[cleanup] Remove out of date comment

Bug: v8:8834
Change-Id: I76d952685f5172844fb0f3189078c0a0bc764b41
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1559746Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Maciej Goszczycki <goszczycki@google.com>
Cr-Commit-Position: refs/heads/master@{#60823}

src/heap/spaces.h

@@ -1577,10 +1577,6 @@ extern template EXPORT_TEMPLATE_DECLARE(
 // -----------------------------------------------------------------------------
 // Interface for heap object iterator to be implemented by all object space
 // object iterators.
-//
-// NOTE: The space specific object iterators also implements the own next()
-//       method which is used to avoid using virtual functions
-//       iterating a specific space.
 
 class V8_EXPORT_PRIVATE ObjectIterator : public Malloced {
  public: