I don't recall why I added this. Possibly in a confused effort
to match /tests/phpunit, except /tests/phpunit/suites is not
where test cases live, they live under /tests/phpunit/* directly,
mostly /tests/phpunit/includes named after the source directory.
The correct equivalent to that is /tests/qunit/resources for JS.
While at it, also remove mention of this concept from various other
places where it doesn't add value. It's one more word/concept to
learn, process, understand, or translate mentally. They're just tests,
or for the one or two places where we care about how they are
internally transmitted, a "test module".
Bug: T250045
Change-Id: I5ea22e4965d190357aa69883f29f9049ee8ebf13
68d4fe68b9