This is accomplished without JavaScript.

There’s a script tag on the builds page that reloads the page every second, according to the page source. How is that not JavaScript?

The key to doing it without JavaScript is this:

<meta id="refresh" http-equiv="refresh" content="5">

The script you found removes it and does it a different way so it can scroll to the bottom. Optional progressive enhancement.

Ah, optional JavaScript. Makes sense

Even if it did have JS, I think most of the crowd would be fine with minimal JS also, since there are some legitimate use cases. Having JS is not the end of the world, but today's standard is to completely abuse it, leading to horrifically bloated websites.