Add weekly build/test scripts

[AlexanderRichert-NOAA]

Summary

This PR will add scripting for weekly unit testing and build caching of the unified env through Jenkins, cron jobs, etc.

Also a few updates for Acorn, including a change to spack stack create env --compiler that allows compiler version to be specified (spack stack create env --compiler intel -> envs/myenv-intel; spack stack create env --compiler intel@2022 -> envs/myenv-intel-2022), which is needed to differentiate on platforms platform where more than one version of a compiler is installed.

To-do list:

• Set up script for running at least one UWM RT that runs s2swa (cpld_control_p8? should include MAPL, Scotch; see UWM testing in weekly builds #1303).
• Figure out how best to track results so we don't get in the habit of ignoring failing unit tests (Slack integration?)

Testing/implementation by platform

On each system:

• Configure ShellSetup.sh (including setting centralized build_cache dir under spack-stack/ dir)
• Set up centralized source cache
• Get it running (Jenkins, cron, GHA); test installing a few packages
• Enable notifications (email, Slack, whatever)

Platforms (check when all of the above items are complete):

• Acorn - @AlexanderRichert-NOAA - cron
• Orion - @rickgrubin-tomorrow test with Jenkins on Orion
• Nautilus - @climbfuji - either cron or Github actions

Applications affected

all

Systems affected

all (eventually)

Dependencies

none

Issue(s) addressed

#1184, #365

Checklist

• This PR addresses one issue/problem/enhancement, or has a very good reason for not doing so.
• These changes have been tested on the affected systems and applications.
• All dependency PRs/issues have been resolved and this PR can be merged.

[AlexanderRichert-NOAA]

closing temporarily so I don't spam the CI with jobs...

[AlexanderRichert-NOAA]

Cron entry for Acorn: 0 1 * * SUN /path/to/spack-stack-weekly-build/util/weekly_build/SpackStackBuildCache_AllSteps.sh $(date +\%y\%m\%d) /path/to/spack-stack/weekly_build acorn > /path/to/spack-stack/weekly_build/logs/cron.$(date +\%y\%m\%d).out 2>&1

[climbfuji]

@AlexanderRichert-NOAA I am pulling in the latest updates from develop once more