Add support for gcc@14

[climbfuji]

Description

This PR adds support for gcc@14 for the three environment templates unified-dev, neptune-dev, cylc-dev.

This requires an update for spack-packages, see JCSDA/spack-packages#52.

Tested on my laptop with gcc@14 running Almalinux 9 under WSL2.

Dependencies

• Waiting on Bugfix to compile py-protobuf@4.24.4 with gcc@14 spack-packages#52

Issues addressed

Support for gcc@14 was identified as one of the main goals for spack-stack-2.2.0.

Applications affected

None

Systems affected

My laptop only (no tier-1 system is using gcc@14 yet to my knowledge)

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 will be made (compiler compatibility matrix)

[climbfuji]

@AlexanderRichert-NOAA Ready for your review whenever you are. Thanks!