patch 8.2.3308: Vim9: no runtime check for argument type with varargs only

Problem:    Vim9: no runtime check for argument type if a function only has
            varargs.
Solution:   Also check argument types if uf_va_type is set. (closes #8715)

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3308,
 /**/
     3307,
 /**/