Migrate away from VoidWorks

This is one last hanging piece of work left over from last year's Java 8
migration. There's no functionality changes in this CL, just refactoring.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=201947600

java/google/registry/tools/server/DeleteEntityAction.java

@@ -25,7 +25,6 @@ import com.google.appengine.api.datastore.KeyFactory;
 import com.google.common.base.Splitter;
 import com.google.common.collect.ImmutableList;
 import com.google.common.flogger.FluentLogger;
-import com.googlecode.objectify.VoidWork;
 import com.googlecode.objectify.impl.EntityMetadata;
 import google.registry.request.Action;
 import google.registry.request.HttpException.BadRequestException;
@@ -90,11 +89,7 @@ public class DeleteEntityAction implements Runnable {
     getDatastoreService().delete(rawDeletions);
     // Delete ofy entities.
     final ImmutableList<Object> ofyDeletions = ofyDeletionsBuilder.build();
-    ofy().transactNew(new VoidWork() {
-        @Override
-        public void vrun() {
-          ofy().delete().entities(ofyDeletions).now();
-        }});
+    ofy().transactNew(() -> ofy().delete().entities(ofyDeletions).now());
     String message = String.format(
         "Deleted %d raw entities and %d registered entities",
         rawDeletions.size(),