how to determine if light-dark() css is supported officially?

:root {
  /* this has to be set to switch between light or dark */
  color-scheme: light dark;
  --light-bg: ghostwhite;
  --light-color: darkslategray;
  --light-code: tomato;
  --dark-bg: darkslategray;
  --dark-color: ghostwhite;
  --dark-code: gold;
}

* {
  background-color: light-dark(var(--light-bg), var(--dark-bg));
  color: light-dark(var(--light-color), var(--dark-color));
}

code {
  color: light-dark(var(--light-code), var(--dark-code));
}

<h1><code>light-dark()</code> CSS function</h1>
<section>
  <h2>Automatic</h2>
  <p>This section will react to the users system or user agent setting.</p>
</section>
<section class="light">
  <h2>Light</h2>
  <p>
    This section will be light due to the <code>color-scheme: light;</code>.
  </p>
</section>
<section class="dark">
  <h2>Dark</h2>
  <p>This section will be dark due to the <code>color-scheme: dark;</code>.</p>
</section>