Add periodic removal of older thumbnails for preview cards (#11304)

app/workers/maintenance/uncache_preview_worker.rb

@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class Maintenance::UncachePreviewWorker
+  include Sidekiq::Worker
+
+  sidekiq_options queue: 'pull'
+
+  def perform(preview_card_id)
+    preview_card = PreviewCard.find(preview_card_id)
+
+    return if preview_card.image.blank?
+
+    preview_card.image.destroy
+    preview_card.save
+  rescue ActiveRecord::RecordNotFound
+    true
+  end
+end