[develop] Fix the meta gempak job so it can run in production mode

[DavidHuber-NOAA]

Description

The gempak meta job, when run in production, is intended to run alongside the GFS forecast and run as different forecast intervals are passed. This capability was not tested during development and this PR fixes it.

Refs #4436

Type of change

• Bug fix (fixes something broken)
• New feature (adds functionality)
• Maintenance (code refactor, clean-up, new CI test, etc.)

Change characteristics

• Is this change expected to change outputs NO
• Is this a breaking change (a change in existing functionality)? NO
• Does this change require a documentation update? NO
• Does this change require an update to any of the following submodules? NO

How has this been tested?

Ran the gempakmeta job in a production-like manner within the C96_atm3DVar_extended test.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• New and existing tests pass with my changes
• (NO, this must be run separately) This change is covered by an existing CI test or a new one has been added

[DavidHuber-NOAA]

I have tested this in a production-like configuration and shown that the gempakmeta job now runs correctly in that manner. Opening for review.

[DavidHuber-NOAA]

Both extended tests passed on WCOSS2 in both production-like and development modes.

[ChristopherHill-NOAA]

Thank you for the update, @DavidHuber-NOAA. I will complete my review for this PR on Wednesday (04/08).
cc: @sbanihash

[DavidHuber-NOAA]

Thank you @ChristopherHill-NOAA!

[ChristopherHill-NOAA]

This existing if-block may be redundant with the if-block in new file config.gempakmeta.