title: Invalid property ... set to ... Missing plugin? gsap.registerPlugin()
body: <p>In Vue3, if I try a <code>gsap</code> animation in the <code>mounted()</code> lifecycle hook, it works, but if I try it in the <code>onMounted</code> hook inside <code>setup</code>, I get these warnings:</p>
  <pre><code>Invalid property rotationY set to 45 Missing plugin? gsap.registerPlugin()
  Invalid property rotationX set to 45 Missing plugin? gsap.registerPlugin()
  </code></pre>
  <hr />
  <p>My <code>setup</code>:</p>
  <pre class="lang-js prettyprint-override"><code>setup() {
      const comments = ref(null);
      const test = function() {
          gsap.fromTo(
              comments,
              { rotationY: 45 },
              {
                  rotationX: 45,
                  ease: 'back.in(1)',
              },
              'mousein'
          );
      };
  
      onMounted(test);
  
      return { comments };
  },
  </code></pre>
  <p>The Vue docs say <code>onMounted</code> inside <code>setup</code> is the same as <code>mounted()</code>, so how could I be getting different results?</p>