patch 8.2.1160: Vim9: memory leak in allocated types

Problem:    Vim9: memory leak in allocated types.
Solution:   Free the type pointers.
diff --git a/src/vim9script.c b/src/vim9script.c
index 77fe6b0..c191113 100644
--- a/src/vim9script.c
+++ b/src/vim9script.c
@@ -126,7 +126,7 @@
     }
     ga_clear(&si->sn_imports);
     ga_clear(&si->sn_var_vals);
-    ga_clear(&si->sn_type_list);
+    clear_type_list(&si->sn_type_list);
 }
 
 /*