cppgc: Remove deprecated enum values

Bug: chromium:1056170
Change-Id: I74c589171470296d310055ba3fe982fb3c9f25f4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2642261Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72233}

include/cppgc/common.h

@@ -14,11 +14,6 @@ namespace cppgc {
 enum class EmbedderStackState {
   kMayContainHeapPointers,
   kNoHeapPointers,
-  kUnknown V8_ENUM_DEPRECATED("Use kMayContainHeapPointers") =
-      kMayContainHeapPointers,
-  kNonEmpty V8_ENUM_DEPRECATED("Use kMayContainHeapPointers") =
-      kMayContainHeapPointers,
-  kEmpty V8_ENUM_DEPRECATED("Use kNoHeapPointers") = kNoHeapPointers,
 };
 
 }  // namespace cppgc