Separate CCPP schemes cannot share namelist groups

### What happened?

Trying to set up namelist xml for two separate schemes where `` is the same for these two schemes will result in a build time error.

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

Create two CCPP schemes and corresponding `scheme1_namelist.xml` `scheme2_namelist.xml` files

Create two different namelist entries in these two xml files, but with the same `` (e.g., `fruit_nl`)

Try to build

Error will be similar to
```
atm_in_paramgen.AtmInParamGenError: Cannot append:
'/home/hplin/2411_sima_check-energy/CAM-SIMA.rebase/src/physics/ncar_ccpp/schemes/check_energy/check_energy_chng_namelist.xml'
The following namelist groups conflict with those in
'/home/hplin/2411_sima_check-energy/CAM-SIMA.rebase/src/physics/ncar_ccpp/schemes/sima_diagnostics/check_energy_gmean_diagnostics_namelist.xml :'
check_energy_nl
```

### What CAM-SIMA hash were you using?

623ef7b3

### What machine were you running CAM-SIMA on?

CGD machine (e.g. izumi)

### What compiler were you using?

GNU

### Path to a case directory, if applicable

_No response_

### Will you be addressing this bug yourself?

Any Software Engineer can do this

### Extra info

_No response_