drm/ci: Add jobs to run KUnit tests

Add jobs to run KUnit tests using tools/testing/kunit/kunit.py tool.

Signed-off-by: Vignesh Raman <vignesh.raman@collabora.com>
Acked-by: Helen Koike <helen.fornazier@gmail.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20250623085033.39680-3-vignesh.raman@collabora.com


Signed-off-by: Maxime Ripard <mripard@kernel.org>