keras/src/utils/tracking.py/Tracker/untrack
class Tracker:    def untrack(self, value):
        for store_name in self.stored_ids.keys():
            if id(value) in self.stored_ids[store_name]:
                self.stored_ids[store_name].remove(id(value))
                python_utils.remove_by_id(self.config[store_name][1], value)