Are we sure we want to remove the padding from .wp-code-block? i.e. is this the behavior you want to achieve? With the plugin disabled, here's what a code block looks like:

With this branch enabled, here's what the code block looks like now.

Yes, as without the changes in this PR does not the second screenshot show a border outlining the with white padding inside?

Correct, without this PR, it looks like so.

I just wanted to make sure this was the intended behavior. If it is, then should we also remove any borders from .wp-code-blocks? Because otherwise, we could end up with something like this,

Where is that border radius coming from?

The Twenty Twenty stylesheet

Ah, yes, I see that now:

code,
kbd,
samp {
	background: rgba(0, 0, 0, 0.075);
	border-radius: 0.2rem;
}