Prune dictionary layouts for missing list values

[JSap0914]

Rationale for this change

Dictionary layouts currently return the input pruning mask for list_contains, even when evaluating the expression against the dictionary values proves that no encoded row can match. This forces scans to fetch and evaluate the codes unnecessarily.

Fixes #3953

What changes are included in this PR?

• Evaluate list_contains against the dictionary values during pruning.
• Return an all-false mask when no dictionary value matches; otherwise preserve the input mask.
• Verify both matching and non-matching cases and assert that pruning never requests code segments.

What APIs are changed? Are there any user-facing changes?

No public APIs change. Dictionary-backed scans can now skip code reads when membership is impossible.

Validation

• cargo nextest run -p vortex-layout list_contains_pruning_uses_only_dictionary_values
• cargo nextest run -p vortex-layout (134 passed)
• cargo clippy -p vortex-layout --all-targets --all-features -- -D warnings
• cargo +nightly fmt -p vortex-layout -- --check
• git diff --check

AI assistance

This change was developed with agentic coding assistance and reviewed and tested by the contributor.