Issue #2031437 by fgm, benjy: Fixed Blocks no longer use 'delta'. Remove it...

Issue #2031437 by fgm, benjy: Fixed Blocks no longer use 'delta'. Remove it from derivative plugins.

core/modules/aggregator/lib/Drupal/aggregator/Plugin/Derivative/AggregatorCategoryBlock.php

@@ -83,7 +83,6 @@ public function getDerivativeDefinition($derivative_id, array $base_plugin_defin
     }
     $result = $this->connection->query('SELECT cid, title FROM {aggregator_category} ORDER BY title WHERE cid = :cid', array(':cid' => $derivative_id))->fetchObject();
     $this->derivatives[$derivative_id] = $base_plugin_definition;
-    $this->derivatives[$derivative_id]['delta'] = $result->cid;
     $this->derivatives[$derivative_id]['admin_label'] = $this->translationManager->translate('@title category latest items', array('@title' => $result->title));
     return $this->derivatives[$derivative_id];
   }
@@ -96,7 +95,6 @@ public function getDerivativeDefinitions(array $base_plugin_definition) {
     $result = $this->connection->query('SELECT cid, title FROM {aggregator_category} ORDER BY title');
     foreach ($result as $category) {
       $this->derivatives[$category->cid] = $base_plugin_definition;
-      $this->derivatives[$category->cid]['delta'] = $category->cid;
       $this->derivatives[$category->cid]['admin_label'] = $this->translationManager->translate('@title category latest items', array('@title' => $category->title));
     }
     return $this->derivatives;

core/modules/system/lib/Drupal/system/Plugin/Derivative/SystemMenuBlock.php

@@ -25,7 +25,6 @@ public function getDerivativeDefinitions(array $base_plugin_definition) {
       // menu would otherwise clash with the 'main' page content block.
       $menu_key = 'menu-' . $menu;
       $this->derivatives[$menu_key] = $base_plugin_definition;
-      $this->derivatives[$menu_key]['delta'] = $menu_key;
       // It is possible that users changed the menu label. Fall back on the
       // built-in menu label if the entity was not found.
       $entity = entity_load('menu', $menu);