Have an option to not run git commands during the build process

[harshula]

exp/MOM_compile.csh calls exp/version_compile.csh and that calls exp/update_version.csh

exp/update_version.csh:

set old_hash=`grep 'public :: MOM_COMMIT_HASH' ../src/version/version.F90 | cut -d '"' -f 2 | cut -d '=' -f 2`
set new_hash=`git rev-parse HEAD`

[harshula]

This commit in the development branch removes git execution during the build: 926d370

[harshula]

The development branch commit has been accidentally merged to main via PR #6

[aidanheerdegen]

There is a related issue on the upstream mom-ocean#308

I will put in a fix there and rebase/merge those changes into our fork.

[aidanheerdegen]

This is the upstream PR

mom-ocean#384

[harshula]

Commit d7ba13a