Fix crash in downloaded podcasts below API 34

Signed-off-by: Unpublished <[email protected]>

News-Android-App/src/main/java/de/luhmer/owncloudnewsreader/NewsReaderDetailFragment.java

@@ -539,7 +539,7 @@ protected List<RssItem> doInBackground(Void... voids) {
                 items = items.stream().filter((rss) -> {
                     var podcast = DatabaseConnectionOrm.ParsePodcastItemFromRssItem(mActivity, rss);
                     return podcast.offlineCached;
-                }).toList();
+                }).collect(Collectors.toList());
             }
 
             sw.stop();