Remove TransportOptions from ActionType (elastic#97721)

This wasn't actually used on this class, inlined the single use case.
This sets up a follow-up with a massive code saving, there really is no
need to subclass this class 400+ times :) I'll open a PR for that once
this is in, it's an easy automatic cleanup.

server/src/main/java/org/elasticsearch/action/ActionType.java

@@ -9,7 +9,6 @@
 package org.elasticsearch.action;
 
 import org.elasticsearch.common.io.stream.Writeable;
-import org.elasticsearch.transport.TransportRequestOptions;
 
 /**
  * A generic action. Should strive to make it a singleton.
@@ -42,13 +41,6 @@ public Writeable.Reader<Response> getResponseReader() {
         return responseReader;
     }
 
-    /**
-     * Optional request options for the action.
-     */
-    public TransportRequestOptions transportOptions() {
-        return TransportRequestOptions.EMPTY;
-    }
-
     @Override
     public boolean equals(Object o) {
         return o instanceof ActionType && name.equals(((ActionType<?>) o).name());

server/src/main/java/org/elasticsearch/action/bulk/BulkAction.java

@@ -25,8 +25,4 @@ private BulkAction() {
         super(NAME, BulkResponse::new);
     }
 
-    @Override
-    public TransportRequestOptions transportOptions() {
-        return TRANSPORT_REQUEST_OPTIONS;
-    }
 }

server/src/main/java/org/elasticsearch/action/bulk/TransportShardBulkAction.java

@@ -117,9 +117,14 @@ public TransportShardBulkAction(
         this.postWriteAction = WriteAckDelay.create(settings, threadPool);
     }
 
+    private static final TransportRequestOptions TRANSPORT_REQUEST_OPTIONS = TransportRequestOptions.of(
+        null,
+        TransportRequestOptions.Type.BULK
+    );
+
     @Override
     protected TransportRequestOptions transportOptions() {
-        return BulkAction.INSTANCE.transportOptions();
+        return TRANSPORT_REQUEST_OPTIONS;
     }
 
     @Override