How to clear heap memory in flutter web?

Im working on flutter web.I need to know how to clear heap memory in flutter web. I have used simple text widget but it takes 144mb as heap. I dont know where from it comes. My code:

import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(
    title: 'Demo',
    home: Text('hi'),
  ));
}

I have attached pictures for reference

kindly tell me how to clear this memory.