Drop the start-up pass that folds files WordPress listed twice (#83)

Before 0.6.0 the parser took WordPress's numbered player URLs (?_=2) for
separate files and downloaded some episodes twice. Since then it drops
the repeats while reading (same_file_key), and merge_repeated_enclosures
cleaned up what was already stored. Production has run it; on every
start since it has only cost a query that finds nothing.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -30,6 +30,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - The logo is in the top bar beside the add-feed button, in place of the name at the top of the
   feed list. Hovering it shows iPX's version.
 
+### Removed
+
+- Starting up no longer looks for files downloaded twice before 0.6.0 read WordPress's player
+  links correctly; that clean-up has run.
+
 ### Fixed
 
 - A feed whose website names an icon that is missing shows the site's `/favicon.ico` instead of