Restore constraint on map formatter (#4326)

* Restore constraint on map formatter
* Remove unnecessary double parens

include/fmt/ranges.h

@@ -527,7 +527,9 @@ struct formatter<
 template <typename R, typename Char>
 struct formatter<
     R, Char,
-    enable_if_t<range_format_kind<R, Char>::value == range_format::map>> {
+    enable_if_t<conjunction<
+        bool_constant<range_format_kind<R, Char>::value == range_format::map>,
+        detail::is_formattable_delayed<R, Char>>::value>> {
  private:
   using map_type = detail::maybe_const_range<R>;
   using element_type = detail::uncvref_type<map_type>;