Document option to improve phpunit information in log
The PHPUnit job log output could be improved. Two things specifically
(a) There is no listing of which tests have been run. This would be helpful in the cases where the phpunit job has been split into parallel streams via the matrix. If a test `@group` has been missed or typed wrongly we have no idea which tests were attempted. There are also other ways to filter tests, and having some listing of which test were run would be very useful.
(b) The progress of tests results in a very lng empty log, one dot is written per line. It's tedious to have to scroll through the empty log. See https://git.drupalcode.org/project/scheduler/-/jobs/46196 as an example. I am sure there is a way to make the progress output not throw a newline for every test.
Resolution
Add documentation to allow maintainers to change the format of the phpunit output to a more readable one when using the phpunit binary.