This integration test contains three issues:
- The `page.bringToFront()` call is not awaited, even though it returns
a promise (see https://pptr.dev/api/puppeteer.page.bringtofront). Note
that in other tests we do this correctly already.
- The `page.waitForSelector()` call at the end is unnecessary because
that exact condition is already checked at the end of the
`waitForImage` function we call just before this line; see
https://github.com/mozilla/pdf.js/blob/master/test/integration/stamp_editor_spec.mjs#L74.
- The pages should be closed in reversed order; please refer to the
description in #18318 for more details.
Fixes#18318.
287fd6afd4