Replace 2 transpose() with 1 permute in TransformerBlock()`

[dingyiwei]

As discussed in the comment of #2329, using permute() to change dimensions of the feature in TransformerBlock instead of 2 transpose()s looks more elegant and readable.

🛠️ PR Summary

_{Made with ❤️ by Ultralytics Actions}

🌟 Summary

Enhanced tensor manipulation for efficiency in YOLOv5 models.

📊 Key Changes

• Replaced a sequence of tensor operations (unsqueeze, transpose, squeeze) with a single permute operation.
• Simplified tensor reshaping in forward method to improve code readability.

🎯 Purpose & Impact

• 🔍 Clarity: The new tensor operations are easier to understand.
• ⚡ Performance: Could potentially increase the efficiency of the model by using less memory-intensive tensor operations.
• 🛠 Maintainability: Simpler codebase for future updates and maintenance.

[glenn-jocher]

/rebase

[glenn-jocher]

@dingyiwei PR is merged. Thank you for your contributions to YOLOv5 🚀 and Vision AI ⭐