Fix an issue with "nextPage()" on worker trigger queries

Ref T13266. We never page these queries, and previously never reached the
"nextPage()" method. The call order changed recently and this method is now
reachable. For now, just no-op it rather than throwing.

src/infrastructure/daemon/workers/query/PhabricatorWorkerTriggerQuery.php

@@ -70,7 +70,11 @@ final class PhabricatorWorkerTriggerQuery
   protected function nextPage(array $page) {
     // NOTE: We don't implement paging because we don't currently ever need
     // it and paging ORDER_EXECUTION is a hassle.
-    throw new PhutilMethodNotImplementedException();
+
+    // (Before T13266, we raised an exception here, but since "nextPage()" is
+    // now called even if we don't page we can't do that anymore. Just do
+    // nothing instead.)
+    return null;
   }
 
   protected function loadPage() {