Remove "// TODO RANDOMIZE with flush" comment (#93752)

This TODO is here for nearly 10 years and tests expect refresh() 
to effectively make document searchable.

test/framework/src/main/java/org/elasticsearch/test/ESIntegTestCase.java

@@ -1384,7 +1384,6 @@ public abstract class ESIntegTestCase extends ESTestCase {
      */
     protected final RefreshResponse refresh(String... indices) {
         waitForRelocation();
-        // TODO RANDOMIZE with flush?
         RefreshResponse actionGet = client().admin()
             .indices()
             .prepareRefresh(indices)