tests: reduce concurrency for flaky bud-multiple-platform-no-run
tests: reduce concurrency for flaky bud-multiple-platform-no-run

We have a recorded bug here https://github.com/containers/buildah/issues/3710
but complexity of this bug fix is looking high as of now with fixes
going into multiple components.

See dicsussion here: https://github.com/containers/buildah/issues/3710

Reducing jobs for this test will ensure that we process things in serial
order so instead of skipping this test we can still run it in a serial
manner and with no flakes

Signed-off-by: Aditya R <4f9683854fe0b71db89677d592545c6b565c2266@redhat.com>

TomSweeneyRedHat/buildah,rhatdan/buildah,rhatdan/buildah,TomSweeneyRedHat/buildah,nalind/buildah-1,nalind/buildah-1,nalind/buildah-1,TomSweeneyRedHat/buildah,rhatdan/buildah