patch 8.2.3704: Vim9: cannot use a list declaration in a :def function

Problem:    Vim9: cannot use a list declaration in a :def function.
Solution:   Make it work.

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3704,
 /**/
     3703,
 /**/