patch 8.2.1190: Vim9: checking for Vim9 syntax is spread out

Problem:    Vim9: checking for Vim9 syntax is spread out.
Solution:   Use in_vim9script().
diff --git a/src/list.c b/src/list.c
index e8d5f5f..9a334ae 100644
--- a/src/list.c
+++ b/src/list.c
@@ -1167,7 +1167,7 @@
     list_T	*l = NULL;
     typval_T	tv;
     listitem_T	*item;
-    int		vim9script = current_sctx.sc_version == SCRIPT_VERSION_VIM9;
+    int		vim9script = in_vim9script();
     int		had_comma;
 
     if (evaluate)