NMS unused variable fix

[glenn-jocher]

🛠️ PR Summary

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🌟 Summary

Refinement of Non-Maximum Suppression (NMS) functionality in YOLOv5.

📊 Key Changes

• Improved the NMS documentation string to more accurately describe its purpose.
• Removed the minimum dimension constraint (min_wh) check for bounding boxes.
• Cleaned up code by eliminating unused warning timer logic for NMS processing time.

🎯 Purpose & Impact

• Clarifies the description of NMS to help users understand its function (rejecting overlapping bounding boxes).
• Simplifies the NMS function by not enforcing a minimum box width and height, potentially reducing false negatives (legitimate detections being discarded).
• Streamlines the time limit warning in NMS, making the log message consistent and removing the condition that obscured repetitive warnings. This cleans up the warnings and maintains user awareness when the time limit is exceeded, without spamming the log.