patch 8.2.1616: Vim9: cannot pass "true" to synID()

Problem:    Vim9: cannot pass "true" to synID().
Solution:   Use tv_get_bool_chk(). (closes #6860)

src/version.c

@@ -754,6 +754,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1616,
 /**/
     1615,
 /**/