Changed `VALID_REALMS` field from 'atmosphere' to 'atmos'

[CodeGat]

Noting error here: https://github.com/ACCESS-NRI/access-esm1.5-configs/pull/43/checks?check_run_id=28637397532

In this PR:

• Updated the VALID_REALMS to their CMIP7 equivalents
• Update version to 0.0.6

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 73.48%. Comparing base (8f2fb04) to head (f2f37d9). Report is 1 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #46 +/- ## ======================================= Coverage 73.48% 73.48% ======================================= Files 15 15 Lines 724 724 ======================================= Hits 532 532 Misses 192 192 ```

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