patch 8.2.2693: Vim9: locked script variable can be changed

Problem:    Vim9: locked script variable can be changed.
Solution:   Check legacy script variable for being locked. (issue #8031)
diff --git a/src/version.c b/src/version.c
index 1059585..760a0f4 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2693,
+/**/
     2692,
 /**/
     2691,