Intermittent PASS in `/css/css-animations/event-order.tentative.html`

```
Stable unexpected results (1): 
  ▶ OK /css/css-animations/event-order.tentative.html
  └   ▶ PASS [expected FAIL] Same events on pseudo-elements follow the prescribed order
```
https://github.com/servo/servo/actions/runs/17297708560/job/49100678455