Investigate migrating to self-build debian SLURM packages

[gdevenyi]

I can successfully build the SLURM deb packages, which is quite a bit simpler than our current setup.

https://slurm.schedmd.com/quickstart_admin.html#debuild

If we combine that with a local-path repo like:
https://askubuntu.com/questions/170348/how-to-create-a-local-apt-repository, mounted from the storage system, we can install and globally upgrade SLURM much more smoothly.

Slight complication is building on cicus03, until we upgrade.

[gdevenyi]

Need this patch until they merge it, https://github.com/gdevenyi/slurm/tree/man2html-base

[gdevenyi]

I bet we can make a PPA here of the upstream packages:
https://assafmo.github.io/2019/05/02/ppa-repo-hosted-on-github.html

We can definitely make a git action do this.