No results for Chrome, Firefox or Safari for simple test change

[foolip]

web-platform-tests/wpt#8388 changed a test in a pretty straightforward way. The linked results, however, say "No tests for this job" for Chrome, Firefox and Safari. Here's a screenshot of Firefox:

[foolip]

Calling it roadmap because if this is widespread then the web-platform-tests pull requests have test results from Chrome, Edge, Firefox and Safari within 15 minutes in Nov-Dec would be affected. It's also quite possible to calculate the score for that in a way that ignores whether any tests were actually run, which would be bad too.