Add MOM5 REPRO flags to preserve answers with MOM5 internal FMS

[dougiesquire]

Description
Without the changes in this PR, ACCESS models built with the "internal" FMS included in the MOM5 repo give different answers than ACCESS models using "external" FMS in this repo - see here. This PR adds the MOM5 REPRO compiler flags so that answers can be preserved when moving from internal to external FMS.

How Has This Been Tested?
I have successfully reproduced answers from released versions of ACCESS-OM2 using these changes (this change to the access-fms SPR is also needed if using Spack)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code

[harshula]

Hi @dougiesquire , In MOM5, -fp-model precise -fp-model source appears to be set only when variant restart_repro is true (default). Should we have a similar variant for FMS? Will someone want to run MOM5 with restart_repro set to false?

[dougiesquire]

Will someone want to run MOM5 with restart_repro set to false?

I don't think so. I removed the option from the MOM5 CMake build system and have the restart repro flags set always - see here.