Include containers in fat image

[sjpb]

• Container images are pulled during fat image build and before service start to avoid service start failures from slow pulls / docker.io rate limits.
• Can disable base OS package updates during image build to speed-up debugging.

New fat image build openhpc-240112-1705-1f2656f5:

• Includes container images, as above.
• Now requires 12GB root disk.
• Includes OpenHPC v2.7.1, which provides Slurm 22.05.11 addressing Slurm CVE-2023-49933 through CVE-2023-49938

[sjpb]

Image build: https://github.com/stackhpc/ansible-slurm-appliance/actions/runs/7505190440 openhpc-240112-1705-1f2656f5

[sjpb]

Checked @ 1f2656f on a "local", non-CI cluster using image openhpc-240112-1705-1f2656f5 that monitoring works ok; jobs dashboard and a jobs detail all shows expected data.

Checked that image build for openhpc-240112-1705-1f2656f5 actually did package updates.

[sjpb]

Replaced by #351