GitLab

Upstream WPT has recently upgraded to pytest v4:
https://github.com/web-platform-tests/wpt/pull/26704

Also take this chance to upgrade some other wheels used by WPT to the
latest we have in CIPD, and remove a duplicate psutil spec.

Change-Id: I102fd4b6717fdb1b778f92933afb4c7cf74f834a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2592134Reviewed-by: John Chen <johnchen@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Commit-Queue: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837157}