fix: score value race condition

[vabruzzo]

Fix score_value stop condition race with concurrent trials

Key Changes:

• Fixed score_value() to filter for finished trials before checking thresholds, preventing false negatives with concurrency
• Aligns implementation pattern with score_plateau() which already handles this correctly

Changed:

• dreadnode/optimization/stop.py: Filter to finished_trials before checking score thresholds in score_value()

Bug Details:
When running with concurrency > 1, trials are added to the list in start order but complete out of order. The original code checked trials[-1] which could be a still-running trial when another trial completes.

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Generated Summary:

• In the stop.py, refined the logic to check for finished trials before proceeding, ensuring only completed trials are considered in the stopping criteria.

This summary was generated with ❤️ by rigging