Revert "web/settings/migrate: remove youtubeDubBrowserLang migration"

This reverts commit 94e6acb832.

web/src/lib/settings/migrate.ts

@@ -16,6 +16,7 @@ const oldCheckboxes = [
     'disableAnimations',
     'disableMetadata',
     'plausible_ignore',
+    'ytDub',
     'tiktokH265'
 ] as const;
 
@@ -99,6 +100,7 @@ export const migrateOldSettings = () => {
             tiktokFullAudio: getBool('fullTikTokAudio'),
             tiktokH265: getBool('tiktokH265'),
             disableMetadata: getBool('disableMetadata'),
+            youtubeDubBrowserLang: getBool('ytDub'),
         }
     };