Should results merging happen in CI?

[gsnedders]

Currently, the results processor receives either: a list of wptreport JSON URLs and a list of screenshot URLs, or a single ZIP URL, where the ZIP contains a number of wptreport JSON files and a number of screenshot files.

The results processor then attempts to merge all these files together.

We currently have a bunch of things we ignore when merging all the files together:

https://github.com/web-platform-tests/wpt.fyi/blob/5682248b058b181e1a222595a8125168ff7a3f55/results-processor/wptreport.py#L38-L41

Ideally we'd put the logic somewhere closer to CI where we can actually ignore fields that make sense for that specific configuration.

GitHub Actions also always compresses artifacts, and if we're using multiple jobs for parallelism (the only sensible approach!), then we end up with multiple ZIP files which need to get merged (which we don't currently support).