revert translation.ts: remove unneeded code

Author: zhangyx1998

src/client/theme-default/support/translation.ts

@@ -15,7 +15,6 @@ export function createSearchTranslate(
     const isObject = themeObject && typeof themeObject === 'object'
     const locales =
       (isObject && themeObject.locales?.[localeIndex.value]?.translations) ||
-      (isObject && themeObject?.translations) ||
       null
     const translations = (isObject && themeObject.translations) || null