cppgc: Fix LazySweepingNormalPages

Test was using concurrent sweeper which could lead to the concurrent
sweeper holding onto memory until the allocation succeeded in rare
cases.

Bug: v8:13308
Change-Id: I0f9f93cc503cdc17d6962b3c31bc4ea698b4cb42
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3905183
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83309}

test/unittests/heap/cppgc/sweeper-unittest.cc

@@ -338,7 +338,10 @@ TEST_F(SweeperTest, LazySweepingNormalPages) {
       Heap::Config::CollectionType::kMajor,
       Heap::Config::StackState::kNoHeapPointers,
       Heap::Config::MarkingType::kAtomic,
-      Heap::Config::SweepingType::kIncrementalAndConcurrent};
+      // Sweeping type must not include concurrent as that could lead to the
+      // concurrent sweeper holding onto pages in rare cases which delays
+      // reclamation of objects.
+      Heap::Config::SweepingType::kIncremental};
   Heap::From(GetHeap())->CollectGarbage(config);
   EXPECT_EQ(0u, g_destructor_callcount);
   MakeGarbageCollected<GCedObject>(GetAllocationHandle());