Post-Jammy Downgrade Tweaks

[ilumsden]

Description

This PR performs the following tweaks to the Dockerfiles after the Ubuntu Jammy downgrade:

• Uses the Kitware apt repo to pull CMake 4.0.2 since the normal CMake installed by apt is too old
• Changes the use of benchpark audit -h for bootstrapping out for benchpark bootstrap
• Adds several new utilities, including less, more, and htop
• Changes the entrypoint scripts for the spawn image to only let Flux see a single "node"

[ilumsden]

@slabasan this PR is pretty much ready for review. The one other thing I could add before review and merge is the tag of Benchpark. Let me know if you'd like me to add that to this PR or to a different one.