Split debian-build-testing job
What does this MR do and why?
Split debian-build-testing job
Split the build job from the shader-db tests so that the test
job can be rerun more reliably without hitting the timeout.
Closes: https://gitlab.freedesktop.org/mesa/mesa/issues/9513
Signed-off-by: Vignesh Raman <vignesh.raman@collabora.com>