Bump ESMF to latest beta: esmf@9.0.0b18

[theurich]

Description

This PR updates the repos/builtin submodule to support esmf@9.0.0b18. Environments that previously used esmf@9.0.0b11 are bumped up to esmf@9.0.0b18.

Dependencies

• Waiting on Add esmf@9.0.0b18 and esmf package cherry-pick spack-packages#86

Issues addressed

Resolves #2083

Applications affected

NEPTUNE and GEOS

Systems affected

Not sure.

Testing

• CI: Note whether the automatic tests (GitHub actions tests that run automatically for every commit) pass or not
  • GitHub actions CI tests pass
  • GitHub actions CI tests do not pass (provide explanation)
  • GitHub actions CI tests skipped (provide explanation if necessary)
• New tests added: List and describe any new tests added to GitHub actions
  • ...
• Additional testing: Add information on any additional tests conducted
  • ...

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

[climbfuji]

Thanks very much for the update!