The entire approach behind that test is wrong. Even slight changes in
one pixel can make the test fail. There's no human-friendly way to
determine what the difference between reference and actual frames are.
The reference frame is generated in code rather than from an image on
the disk, which makes the tests even more error-prone.
The test is flaky too and constantly blocks merging patch submissions.
We need a different way to test rendering results, not what
testSceneQPainter currently does. Normally, I would say that we need
to add such an infrastructure before dropping the test, but it makes the
merging process so inconvenient and the test doesn't really bring any
value, it tests really basic cases which are noticeable right away after
launching kwin.
