patch 8.2.0537: Vim9: no check for sandbox when setting v:var

Problem:    Vim9: no check for sandbox when setting v:var.
Solution:   Check for sandbox.
diff --git a/src/version.c b/src/version.c
index 1faac96..fece1a1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -739,6 +739,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    537,
+/**/
     536,
 /**/
     535,