chore(podcasts): drop the dead QueueFeedDownloads wrapper

All callers moved to QueueFeedDownloadsAs in the item-5 commit; the
no-override shim had no remaining callers.

internal/services/podcast_worker.go

@@ -298,12 +298,6 @@ func (w *PodcastDownloadWorker) QueueEpisode(ctx context.Context, episodeID, fee
 	return nil
 }
 
-// QueueFeedDownloads implements "Download All" (D8): queue exactly the
-// non-downloaded set — pending AND failed rows (retry is the same path).
-func (w *PodcastDownloadWorker) QueueFeedDownloads(ctx context.Context, feedID pgtype.UUID) (int, error) {
-	return w.QueueFeedDownloadsAs(ctx, pgtype.UUID{}, feedID)
-}
-
 // QueueFeedDownloadsAs is Download All honoring the CALLER's listening
 // order (§0 item 5b): episodes queue in the feed's effective order (the
 // caller's override, feed-native fallback). Tickets (§0 item 4) make