Was missed from the removal of PHPUnitWrapper:
a16588aac3
Original reason for this: Don't fail dev/build without phpunit
When you install a SilverStripe project with "composer install --no-dev",
the PHPUnit dependency gets skipped. Which means the PHPUnit_Framework_TestListener
interface doesn't exist. The SilverStripe Classloader might still include
SapphireTestReporter which relies on this interface, which then breaks execution.
SS3 fixed this by NOT defining the class in the first place.
This has been removed in 2fdc96a0de (diff-82b3f89e8e5ae090c93e9c3a2ba8aa36L3),
as part of a PHPUnit version upgrade - but without an apparent fix to replace this.
0a55ff9f8c