cppgc: Move forward Trace(T*) deprecation

Bug: v8:13089
Change-Id: I271addd3a80feaa40520ab2768a2380c3d7ab62f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3780821
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81939}

include/cppgc/visitor.h

@@ -68,7 +68,7 @@ class V8_EXPORT Visitor {
    * \param member Reference retaining an object.
    */
   template <typename T>
-  V8_DEPRECATE_SOON("Do not use Trace() with raw pointers.")
+  V8_DEPRECATED("Do not use Trace() with raw pointers.")
   void Trace(const T* t) {
     TraceImpl(t);
   }