Fix flaky test_text_query_word_weights and re-enable test

[tylerhutcherson]

Summary

Investigate and fix flakiness in test_text_query_word_weights, then re-enable it in CI.

Level: Beginner

Current State

• The test is currently skipped due to flaky behavior.
• This hides potential correctness regressions in text query weighting behavior.

Proposed Change

• Identify root cause of nondeterminism (ordering, floating-point sensitivity, or environment assumptions).
• Stabilize assertion strategy.
• Remove skip marker and verify reliability across repeated runs.

Definition of Done

• Test is re-enabled.
• Test passes consistently in repeated local runs and CI.
• Full unit suite remains green.

Out of Scope

• Broad refactor of text query architecture.