Filtering by [`status:precondition_failed`](https://wpt.fyi/results/?label=master&label=experimental&aligned&q=status%3Aprecondition_failed) seems to not work, and perhaps never did work. This would be useful for filtering out tests that fail on [`assert_implements_optional`](https://web-platform-tests.org/writing-tests/testharness-api.html#assert_implements_optional).