gh-117376: Partial implementation of deferred reference counting (#117696)

This marks objects as using deferred refrence counting using the
`ob_gc_bits` field in the free-threaded build and collects those objects
during GC.

Objects/typeobject.c

@@ -3581,6 +3581,8 @@ type_new_alloc(type_new_ctx *ctx)
     et->ht_module = NULL;
     et->_ht_tpname = NULL;
 
+    _PyObject_SetDeferredRefcount((PyObject *)et);
+
     return type;
 }