Adds logic to fix a problem in the _long cycles with the updated post script

[MatthewPyle-NOAA]

DESCRIPTION OF CHANGES:

• Introduces an alternate definition for the tm15, tm30, and tm45 subhourly files. These are used if they are found, and the main definition is not found.

TESTS CONDUCTED:

Machines/Platforms:

• WCOSS2
  • Cactus/Dogwood
  • Acorn
• RDHPCS
  • Hera
  • Jet
  • Orion
  • Hercules

Test cases:

• Engineering tests
  • Non-DA engineering test
  • DA engineering test
    • Retro
    • Ensemble
    • Parallel
• RRFS fire weather
• RRFS_A: - tested as a local change to the v1.0.0 system on dogwood. An hourly post job that had failed due to timing out completed normally with this change.
• RRFS_B:
• RTMA:
• Others:

ISSUE:

CONTRIBUTORS (optional):

• Problem reported by @ShunLiu-NOAA

[BenjaminBlake-NOAA]

This logic will likely need to be updated again in the future when the workflow is updated to use the umbrella data structure (those rrfs_post_${envir}_${cyc} directories will no longer exist). Thanks for getting it working in the current version.