color-contrast-matcher is too greedy about excluding labels

**Expected**: In the following code "hallo" and "guttentag" are tested for color contrast:

```html

Guttentag

```

**Actual**: The color-contrast-matches method is a little greedy, and excludes everything that could be used in the accessible name computation as a disabled thing, not just whatever visible label is actually used. This may lead to things not being tested that probably should be.