patch 8.2.1355: Vim9: no error using :let for options and registers

Problem:    Vim9: no error using :let for options and registers.
Solution:   Give an error. (closes #6568)
diff --git a/src/version.c b/src/version.c
index 066724e..c27c94a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1355,
+/**/
     1354,
 /**/
     1353,