Cleanup: remove support for pluralization during gettext resource tra…

…nslation

sphinx/locale/__init__.py

@@ -221,16 +221,13 @@ def setup(app):
 
     .. versionadded:: 1.8
     """
-    def gettext(message: str, *args: Any) -> str:
+    def gettext(message: str) -> str:
         if not is_translator_registered(catalog, namespace):
             # not initialized yet
             return _TranslationProxy(_lazy_translate, catalog, namespace, message)  # type: ignore[return-value]  # NOQA
         else:
             translator = get_translator(catalog, namespace)
-            if len(args) <= 1:
-                return translator.gettext(message)
-            else:  # support pluralization
-                return translator.ngettext(message, args[0], args[1])
+            return translator.gettext(message)
 
     return gettext