Add LAD22 and LAD23 local-authority lookup assets

[anth-volk]

Fixes #488

Creates complete LAD22 and LAD23 display-metadata CSVs without changing the legacy local_authorities_2021.csv or local_authority_weights.h5 files used by API v1. The LAD22 file restores the 17 English predecessor districts; the LAD23 file contains their four successors. Both include all 11 Northern Ireland districts and unique integer map coordinates.

The established private-data upload workflow now publishes both assets.

Test plan:

• uv run --python 3.13 --frozen pytest policyengine_uk_data/tests/test_local_authority_lookup_assets.py -q
• make format

[anth-volk]

Superseded by PolicyEngine/policyengine-sim-api#705. The replacement keeps this temporary Stage 12 behavior in the simulation executor: it packages the reviewed code/name/coordinate data, detects LAD22 or LAD23 from the complete dataset's actual la_code_oa values, and carries that selection as typed artifact metadata. No UK-data publication is required for this stage.

[anth-volk]

Update: the replacement simulation API work is now PolicyEngine/policyengine-sim-api#706. GitHub closed #705 when its branch was renamed.