patch 8.2.0149: maintaining a Vim9 branch separately is more work

Problem:    Maintaining a Vim9 branch separately is more work.
Solution:   Merge the Vim9 script changes.
diff --git a/src/if_lua.c b/src/if_lua.c
index b80b6c9..1eb7a77 100644
--- a/src/if_lua.c
+++ b/src/if_lua.c
@@ -841,8 +841,7 @@
     if (lua_isnil(L, 3)) // remove?
     {
 	vimlist_remove(l, li, li);
-	clear_tv(&li->li_tv);
-	vim_free(li);
+	listitem_free(l, li);
     }
     else
     {