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.

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

java/google/registry/model/ofy/Ofy.java

@@ -309,6 +309,14 @@ public class Ofy {
     throw new AssertionError();  // How on earth did we get here?
   }
 
+  public void transactNewReadOnly(Runnable work) {
+    transactNewReadOnly(
+        () -> {
+          work.run();
+          return null;
+        });
+  }
+
   /** Execute some work in a transactionless context. */
   public <R> R doTransactionless(Work<R> work) {
     try {