Remove non-batch async contact/host deletion actions

They have been superseded by DeleteContactsAndHostsAction.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=134424453

java/google/registry/config/TestRegistryConfig.java

@@ -167,11 +167,6 @@ public class TestRegistryConfig implements RegistryConfig {
     return "TheRegistrar";
   }
 
-  @Override
-  public Duration getAsyncDeleteFlowMapreduceDelay() {
-    return Duration.standardSeconds(90);
-  }
-
   @Override
   public Duration getAsyncFlowFailureBackoff() {
     return Duration.standardMinutes(10);