patch 8.2.4723: the ModeChanged autocmd event is inefficient

Problem:    The ModeChanged autocmd event is inefficient.
Solution:   Avoid allocating memory. (closes #10134)  Rename
            trigger_modechanged() to may_trigger_modechanged().

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4723,
 /**/
     4722,
 /**/