References in theme.json don't work in site editor upon user changes

[oandregal]

In theme.json styles can be referenced to an existing top-level style (docs).

The following example inverts the colors of the site title with respect to the top-level colors:

{
  "styles": {
    "color": {
      "background": "yellow",
      "text": "black"
    },
    "blocks": {
      "core/site-title": {
        "color": {
          "background": { "ref": "styles.color.text" },
          "text": {"ref": "styles.color.background" }
        }
      }
    }
  }
}

This works in the front and editors.

Bug: change the referenced value in the site editor

When the user makes changes to the referenced value, the value doesn't change accordingly:

Gravacao.de.ecra.a.partir.de.12-04-2023.09.36.55.webm

Moreover, upon saving and reloading the site editor, it stops working (it's properly rendered in the front):

[oandregal]

cc @scruffian @adamziel @draganescu @ramonjd @andrewserong per #41696