Add OLMo 3 base model aliases

[abhinav-bellapu]

Description

Adds the two OLMo 3 pretrained base checkpoints requested in #1499 to the legacy HookedTransformer supported-model registry and alias map:

• allenai/Olmo-3-1025-7B / olmo-3-1025-7b
• allenai/Olmo-3-1125-32B / olmo-3-1125-32b

These checkpoints already exist in the TransformerBridge model registry as Olmo3ForCausalLM; this keeps the legacy get_official_model_name alias surface in sync for users calling HookedTransformer.from_pretrained(...) or resolving model aliases.

Fixes #1499

Type of change

• New feature (non-breaking change which adds functionality)

Screenshots

N/A

Checklist:

• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I have not rewritten tests relating to key interfaces which would affect backward compatibility

Validation

• make format
• make check-format
• uv run --python 3.11 pytest tests/unit/test_supported_models.py -q
• uv run --python 3.11 mypy .
• make unit-test
• uv run --python 3.11 python -m transformer_lens.tools.model_registry.alias_drift --all-statuses --format json checked directly that neither base model remains in in_registry_not_aliases

[abhinav-bellapu]

@jlarson4 ready for review