patch 8.2.2621: typval2type() cannot handle recursive structures

Problem:    typval2type() cannot handle recursive structures.
Solution:   Use copyID. (closes #7979)
diff --git a/src/vim9script.c b/src/vim9script.c
index 309d4bd..9366e76 100644
--- a/src/vim9script.c
+++ b/src/vim9script.c
@@ -750,7 +750,7 @@
     if (sv != NULL)
     {
 	if (*type == NULL)
-	    *type = typval2type(tv, &si->sn_type_list);
+	    *type = typval2type(tv, get_copyID(), &si->sn_type_list);
 	sv->sv_type = *type;
     }