Remove bogus deletion of a weak handle that has already been finalized.

runtime/vm/dart_api_impl_test.cc

Index: runtime/vm/dart_api_impl_test.cc
diff --git a/runtime/vm/dart_api_impl_test.cc b/runtime/vm/dart_api_impl_test.cc
index 1b5a5370e8d7c7f4df0a05eaba9942d2d474da20..5f21a98f3c400f6f38fa1985488994e31801b0e6 100644
--- a/runtime/vm/dart_api_impl_test.cc
+++ b/runtime/vm/dart_api_impl_test.cc
@@ -3036,8 +3036,6 @@ TEST_CASE(WeakPersistentHandleExternalAllocationSizeOldspaceGC) {
   // Expect small garbage to be collected.
   EXPECT_EQ(kHugeExternalSize,
             isolate->heap()->ExternalInWords(Heap::kOld) * kWordSize);
-  Dart_DeleteWeakPersistentHandle(reinterpret_cast<Dart_Isolate>(isolate),
-                                  weak);
   Dart_ExitScope();
 }