Issue #3483450 by roderik: Remove bogus $key parameter from generate() calls

src/Processor/MediaReferenceFieldItemProcessor.php

@@ -39,7 +39,7 @@ class MediaReferenceFieldItemProcessor implements CustomElementProcessorWithKeyI
     /** @var \Drupal\media\MediaInterface $media_entity */
     $media_entity = $field_item->entity;
     if ($this->entityIsAccessible($media_entity, $element)) {
-      $media_element = $this->getCustomElementGenerator()->generate($media_entity, $viewMode, $key);
+      $media_element = $this->getCustomElementGenerator()->generate($media_entity, $viewMode);
       // Set element content from media element to avoid a wrapper tag.
       $element->setFromCustomElement($media_element);
     }

src/Processor/ParagraphFieldItemProcessor.php

@@ -39,7 +39,7 @@ class ParagraphFieldItemProcessor implements CustomElementProcessorWithKeyInterf
     /** @var \Drupal\paragraphs\ParagraphInterface $paragraph */
     $paragraph = $field_item->entity;
     if ($this->entityIsAccessible($paragraph, $element)) {
-      $paragraph_element = $this->getCustomElementGenerator()->generate($paragraph, $viewMode, $key);
+      $paragraph_element = $this->getCustomElementGenerator()->generate($paragraph, $viewMode);
       // Set content without wrapping tag.
       $element->setFromCustomElement($paragraph_element);
     }