Turn off FAA grib2 output for ensemble forecasts

[BenjaminBlake-NOAA]

DESCRIPTION OF CHANGES:

• @MatthewPyle-NOAA confirmed that the special FAA grib2 output does not need to be generated for ensemble forecasts and should be turned off. In this PR, logic is added to the run_prdgen ex-script such that the FAA product generation is only called when DO_ENSFCST is set to false.
• These changes have not been tested, but I just added them as local changes to the real-time RRFS_A parallel on Dogwood. So let's make sure they are working before merging this PR.
• We will also want to add these changes to the production/RRFS.v1 branch.

TESTS CONDUCTED:

None yet but will be tested in the real-time system.

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:
• RRFS_B:
• RTMA:
• Others:

ISSUE:

• Fixes issue Turn off special FAA grib2 output for ensemble forecasts #333

[MatthewPyle-NOAA]

Looks good, but will wait for confirmation that it works properly in RRFS_A before merging. Also, we'll want to capture this one in production/RRFS.v1 as well.

[MatthewPyle-NOAA]

06Z cycle without the fix:

ls *f005*.grib2
rrfs.t06z.aviati.f005.conus13km.grib2  rrfs.t06z.m03.prslev.f005.hi.grib2
rrfs.t06z.ififip.f005.ak3km.grib2      rrfs.t06z.m03.prslev.f005.pr.grib2
rrfs.t06z.ififip.f005.conus13km.grib2  rrfs.t06z.m03.testbed.f005.conus.grib2
rrfs.t06z.m03.aviati.f005.grib2        rrfs.t06z.m03.testbed.f005.grib2
rrfs.t06z.m03.ififip.f005.grib2        rrfs.t06z.natlevfaa.f005.na13km.grib2
rrfs.t06z.m03.natlev.f005.grib2        rrfs.t06z.prslevfaa.f005.conus13km.grib2
rrfs.t06z.m03.prslev.f005.ak.grib2     rrfs.t06z.prslevfaa.f005.na13km.grib2
rrfs.t06z.m03.prslev.f005.conus.grib2  rrfs.t06z.prslevfaa.f005.pr32km.grib2
rrfs.t06z.m03.prslev.f005.grib2

12Z cycle with the fix:

ls *f005*.grib2
rrfs.t12z.m03.aviati.f005.grib2        rrfs.t12z.m03.prslev.f005.grib2
rrfs.t12z.m03.ififip.f005.grib2        rrfs.t12z.m03.prslev.f005.hi.grib2
rrfs.t12z.m03.natlev.f005.grib2        rrfs.t12z.m03.prslev.f005.pr.grib2
rrfs.t12z.m03.prslev.f005.ak.grib2     rrfs.t12z.m03.testbed.f005.conus.grib2
rrfs.t12z.m03.prslev.f005.conus.grib2  rrfs.t12z.m03.testbed.f005.grib2

So looks good to merge