patch 8.2.1023: Vim9: redefining a function uses a new index every time

Problem:    Vim9: redefining a function uses a new index every time.
Solution:   When redefining a function clear the contents and re-use the
            index.

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1023,
 /**/
     1022,
 /**/