🌐(i18n) don't keep unused keys

The potential unused keys was the ones from other
PR, but we don't use crowdin with every PR, so we don't
need to keep the unused keys in the translation files.

src/frontend/packages/i18n/i18next-parser.config.mjs

@@ -3,7 +3,7 @@ const config = {
     message: '${key}',
     description: '${description}',
   },
-  keepRemoved: true,
+  keepRemoved: false,
   keySeparator: false,
 };