patch 8.2.2290: Vim9: unlet of global variable cannot be compiled

Problem:    Vim9: unlet of global variable cannot be compiled.
Solution:   Skip over variables that might be defined later. Give an error if
            a subscript is found. (closes #7585)

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2290,
 /**/
     2289,
 /**/