patch 8.2.4500: Vim9: can declare a global variable on the command line

Problem:    Vim9: can declare a global variable on the command line.
Solution:   Disallow declaring a variable on the command line. (closes #9881)
diff --git a/src/version.c b/src/version.c
index c6a9f73..ce9e7e5 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4500,
+/**/
     4499,
 /**/
     4498,