patch 8.2.1615: Vim9: cannot pass "true" to searchdecl()

Problem:    Vim9: cannot pass "true" to searchdecl().
Solution:   use tv_get_bool_chk(). (closes #6881)
diff --git a/src/version.c b/src/version.c
index 750e287..0cce5b2 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1615,
+/**/
     1614,
 /**/
     1613,