GitLab

Remove microbit-v1, qemu-cortex-a53, qemu-cortex-m3, and qemu-cortex-r5
from CI (and the tree in general).  These machines are part of the
meta-zephyr CI now and keeping them here is redundant.  However, keeping
zephyr builds for machines that also have TF-M.
Signed-off-by: Jon Mason <jon.mason@arm.com>