Intermittent OK in `/fetch/fetch-later/activate-after.https.window.html`

```
Stable unexpected results (1): 
  ▶ OK [expected TIMEOUT] /fetch/fetch-later/activate-after.https.window.html
  └   ▶ PASS [expected TIMEOUT] fetchLater() sends out based on activateAfter, even if document is in BFCache.
```
https://github.com/servo/servo/actions/runs/18403262516/job/52438227454