patch 8.2.2654: Vim9: getting a character from a string can be slow

Problem:    Vim9: getting a character from a string can be slow.
Solution:   Avoid a function call to get the character byte size. (#8000)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2654,
 /**/
     2653,
 /**/