Reduce HPSS jobs' memory to 3GB on WCOSS2

[DavidHuber-NOAA]

Description

This reduces the memory request for WCOSS2 HPSS jobs to 3GB to (hopefully) speed up queue time.

Resolves #4288

Type of change

• Bug fix (fixes something broken)
• New feature (adds functionality)
• Maintenance (code refactor, clean-up, new CI test, etc.)

Change characteristics

• Is this change expected to change outputs (e.g. value changes to existing outputs, new files stored in COM, files removed from COM, filename changes, additions/subtractions to archives)? NO
• Is this a breaking change (a change in existing functionality)? NO
• Does this change require a documentation update? NO
• Does this change require an update to any of the following submodules? NO

How has this been tested?

Full suite of tests on WCOSS2 has started.

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• My changes generate no new warnings
• New and existing tests pass with my changes
• This change is covered by an existing CI test or a new one has been added

[DavidHuber-NOAA]

Tests are currently running on WCOSS2 with all archiving jobs enabled. When complete, I will check all logs for any cgroup memory warnings.

[DavidHuber-NOAA]

All tests passed on WCOSS2 except the C96_atm3DVar_extended and C48_S2SW_extended tests with DO_ARCHCOM=YES due to an incorrect gfs_downstream.yaml.j2. This is a known issue and will be resolved by #4258.

Furthermore, a grep for cgroup returned no hits through all of the log files generated by these tests, suggesting no jobs are under-requesting memory (at least within the confines of the CI tests).

After merging this PR and #4258, I will run the next PR CI suite with DO_ARCHCOM=YES and reperform the test for memory request exceedance.