[format.syn] Remove extraneous commas in vformat_to declarations (#4705)

Author: jensmaurer

source/utilities.tex

@@ -19676,9 +19676,9 @@
     Out format_to(Out out, const locale& loc, @\exposid{wformat-string}@<Args...> fmt, const Args&... args);
 
   template<class Out>
-    Out vformat_to(Out out, string_view fmt, format_args, args);
+    Out vformat_to(Out out, string_view fmt, format_args args);
   template<class Out>
-    Out vformat_to(Out out, wstring_view fmt, wformat_args, args);
+    Out vformat_to(Out out, wstring_view fmt, wformat_args args);
   template<class Out>
     Out vformat_to(Out out, const locale& loc, string_view fmt, format_args args);
   template<class Out>