Fix `/streams/transform-streams/errors.any.js`

While working on #36739, there was an attempt to fix this test in [this commit](https://github.com/servo/servo/commit/2a618e64027a6c0810798912110267c2d12f63f5), but it caused other tests to fail and crash.