What is the minimum correct answer for http requests for favicon.ico

I am working on a very simple web server.

So far, I have not found how to disable annoying requests for favicon.ico from chrome.

So, I thought, what is the shortest or fastest response to such a request. Is it possible to simply disconnect after a request for identification favicon.ico. Or is it considered impolite behavior and should be avoided?

Alternatively, I would send message 404. Do I need to send text, or do I need to send at least the information "content length: 0" or can I leave it?

Thank!