MAINT: Restore unit test type check target

[biefan]

Description

• Add a unit-test-only ty override block for runtime validation and mock-heavy test patterns so the Makefile type-check target passes while library code remains strict.
• Move scorer eval CSV class-scoped fixtures to module-level fixtures and reuse module-level CSV file lists, removing pytest 10 deprecation warnings from that test module.

Tests and Documentation

• make ty
• uv run pre-commit run --files pyproject.toml tests/unit/score/test_scorer_eval_csv_schema.py
• uv run -m pytest tests/unit/score/test_scorer_eval_csv_schema.py -W default
• make unit-test

Documentation changes are not applicable for this maintenance-only update.