theme.json: Code block typography fontFamily isn't working

[danieldudzic]

Here's the markup for the code block:

<pre class="wp-block-code"><code></code></pre>

When setting a fontFamily:

"core/code": {
	"typography": {
		"fontFamily": "var(--wp--preset--font-family--base)"
	}
}

The style gets applied to .wp-block-code, but that's the <pre> tag, and this causes the user agent stylesheet
to take precedence:

---

The solution here would be to apply font-family to .wp-block-code code rather than .wp-block-code.

cc: Automattic/themes#3640