In some of our wpt tests (for example see [1]), we register the same animator multiple times which results in error. We should switch to a model that does the animator registration once in the setup similar to [2].

[1] /wpt/animation-worklet/worklet-animation-with-fill-mode.https.html, external/wpt/animation-worklet/current-time.https.html

[2] /wpt/animation-worklet/scroll-timeline-writing-modes.https.html