Switch qemu boot testing to use isar-cip-core

Issue description

At the moment we are running boot tests on qemu arm, arm64 and x86 machines.
Each of these machines uses a deby-cip-core image to boot with.

deby-cip-core isn't going to be maintained much in the future, so we want to switch over to using isar-cip-core instead.
Ideally the latest tagged release should be used.

Useful links:

Useful links

• CI scripts, image and test templates are defined here
• isar-cip-core is here
• Latest build pipelines for isar-cip-core tags are here (the binaries get uploaded to AWS S3)

Acceptance criteria