NAG CAM5 subcolumns test fails since update to match alpha08l externals

### What happened?

Since https://github.com/ESCOMP/CAM/pull/1511

The NAG CAM5 subcolumns test fails the restart comparison. This test works with intel, so we did not fix it for that PR, but it needs to be investigated.

The differences are in the cpl.hi file:
```
/scratch/cluster/cacraig/aux_cam_nag_20260320202120/ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol.GC.aux_cam_nag_20260320202120/run/ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol.GC.aux_cam_nag_20260320202120.cpl.hi.1979-01-01-16200.nc.base.cprnc.out
```

### What are the steps to reproduce the bug?

Run the following commands on Izumi:

```
git clone https://github.com/ESCOMP/CAM.git
cd CAM
git checkout cam_development
bin/git-fleximod update
cd test/system
env CAM_FC=NAG BL_TESTDIR= ./test_driver.sh -f
```

You should then see a baseline restart test failure for test `ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol`

### What CAM tag were you using?

cam6_4_158

### What machine were you running CAM on?

CGD machine (e.g. izumi)

### What compiler were you using?

NAG

### Path to a case directory, if applicable

/scratch/cluster/cacraig/aux_cam_nag_20260320202120/ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol.GC.aux_cam_nag_20260320202120/

### Will you be addressing this bug yourself?

Any CAM SE can do this

### Extra info

_No response_