[class] remove stale TODO

The TODO of implementing static private brands is now obsolete
now that we have implemented static private methods by directly
desugaring the brand check into comparisons between the receiver
and the class constructor in
https://chromium-review.googlesource.com/c/v8/v8/+/1781011

Bug: v8:8330
Change-Id: Id2ab73ef13c67d626ecdfa6792252b5aea3aff45
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2095639Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Joyee Cheung <joyee@igalia.com>
Cr-Commit-Position: refs/heads/master@{#66908}

src/parsing/parser-base.h

@@ -4606,7 +4606,6 @@ typename ParserBase<Impl>::ExpressionT ParserBase<Impl>::ParseClassLiteral(
   }
 
   if (class_info.requires_brand) {
-    // TODO(joyee): implement static brand checking
     class_scope->DeclareBrandVariable(
         ast_value_factory(), IsStaticFlag::kNotStatic, kNoSourcePosition);
   }