[web snap] Fix Bazel build

Bug: v8:11525
NoTry: True
Change-Id: Idee38e400aec4aed1ebf9a25e0416002a05a7a2f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3679258Reviewed-by: Darius Mercadier <dmercadier@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80851}

src/web-snapshot/web-snapshot.cc

@@ -2744,6 +2744,7 @@ void WebSnapshotDeserializer::DeserializeObjects() {
 void WebSnapshotDeserializer::DeserializeObjectElements(
     Handle<JSObject> object, bool map_from_snapshot) {
   auto [elements, elements_kind, length] = DeserializeElements();
+  USE(length);
   // Ensure objects always get HOLEY_ELEMENTS or DICTIONARY_ELEMENTS: don't
   // change the elements kind if it's holey.
   DCHECK(object->HasHoleyElements());