Run more often?

[foolip]

@jgraham wondered in web-platform-tests/interop#667 (comment) why we don't run this more often.

I think I made some effort originally to align the timing so that it would run after results from epoch branches are available, based on the typical delay at the time.

We could run this more often, but I think it's only clearly useful if we also use non-aligned runs.

[gsnedders]

It wasn't at all worthwhile until 84143f5, therefore frequency didn't matter much.