patch 8.2.1606: Vim9: cannot use "true" with has()

Problem:    Vim9: cannot use "true" with has().
Solution:   Use tv_get_bool(). (closes #6876)
diff --git a/src/version.c b/src/version.c
index 69aecec..70f736d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1606,
+/**/
     1605,
 /**/
     1604,