Misc. weekly build updates

[AlexanderRichert-NOAA]

Description

This PR makes a few updates to the weekly builds. It mainly updates the Acorn config, as well as making build cache pushing optional and chmod'ing the whole run directory to ensure everything is deletable (mostly to avoid failures because of annoying GOMODCACHE default permissions).

Dependencies

none

Issues addressed

none

Applications affected

n/a

Systems affected

All, especially Acorn

Testing

• CI: Note whether the automatic tests (GitHub actions tests that run automatically for every commit) pass or not
  • GitHub actions CI tests pass
• Additional testing: Add information on any additional tests conducted
  • will be re-tested on Acorn

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.
• All necessary updates to the documentation (spack-stack wiki) will be made when this PR is merged