Update requirements.txt to comment tensorboard

[glenn-jocher]

🤖 Generated by Copilot at b638a20

Summary

Walkthrough

🛠️ PR Summary

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🌟 Summary

Optional TensorBoard support in requirements and dynamic import for TensorBoard in logger.

📊 Key Changes

• Commented out the TensorBoard requirement in requirements.txt to make the installation optional.
• Changed the import style for TensorBoard's SummaryWriter in utils/loggers/__init__.py to only import if available, with a fallback to a lambda function returning None.

🎯 Purpose & Impact

• Users who don't need TensorBoard can now install YOLOv5 with fewer dependencies, making the installation lighter and potentially resolving conflicts with the specific version of TensorBoard or protobuf.
• The dynamic import means that TensorBoard is only a soft requirement. This could lead to fewer installation issues for users and a more flexible setup for specialized environments. Users who do not use TensorBoard won't notice any differences, while those who use it should ensure it's installed separately.