GHA keeps redacting all occurrences of the word "deno" out of logs
because this is our wpt.fyi username. This is rather annoying, so I am
just hardcoding the username in the CI script.
This adds a daily scheduled CI pipeline that runs WPT tests against
the most recent epochs/daily every night. Results are uploaded to
wpt.fyi.
WPTs are run on all supported platforms, on both stable and canary.
