Convert scripts to `bash`

[KateFriedman-NOAA]

For better supportability on various platforms and consistency, scripts should be converted from ksh/sh to bash. Some are already bash but not all.

FYI, there was an issue with one of the ksh scripts in testing on Gaea. @DavidBurrows-NCO can provide a sample log with the silent failure that occurs. Tagging @ilianagenkova for her awareness.

[DavidBurrows-NCO]

Thanks @KateFriedman-NOAA... @ilianagenkova Kate suggested Hera would be a good platform to place the log on. I've put a gdasprep log at /scratch1/NCEPDEV/nems/David.Burrows/for_iliana. Permissions should be good for you to access. The specific failure is /gpfs/f5/ufs-ard/world-shared/global/glopara/data/git/prepobs/v1.0.2/install/ush/prepobs_makeprepbufr.sh[1620]: syntax error: unexpected operator/operand '=~'. Thanks

[ilianagenkova]

Thanks for opening this issue!

@KateFriedman-NOAA , do you think (off the top of your head) this is similar problem to:
[https://github.com/NOAA-EMC/global-workflow/issues/691]

[KateFriedman-NOAA]

@ilianagenkova Yes and no. That global workflow issue notes that error codes are not being caught on the way out so any error in the prep job won't be caught. So yes, this is likely a silent failure because of that known issue but the error happening in this case is related to ksh.