Fix #944: Add GPU metrics and optimizations to testspeed benchmark

[Tanisha-Sharma005]

Summary

Enhanced testspeed.py benchmark with GPU device information, memory usage reporting, and ray_test.py performance optimizations for better debugging and profiling.

Changes

• GPU Metrics: Reports device name and memory usage (used/total GB)
• Benchmark Summary: Structured performance metrics output
• ray_test.py: Optimized array operations and reduced allocations
• Trace Events: Step-by-step timing for performance analysis

Testing

Verified on NVIDIA RTX 3060 with comprehensive GPU/CPU benchmark comparison.

Closes #944

[google-cla]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

[Tanisha-Sharma005]

@thowell

CLA signed with tanishaasharma20@gmail.com ✅ https://cla.developers.google.com
Git email fixed. Ready for maintainer approval.

Please review & approve!

Thanks!

[thowell]

@Tanisha-Sharma005 thank you for contributing to mujoco warp! closing this pr since we are not planning to merge the pr. if you are interested in contributing further to the project please follow up on issues marked 'good first issue'. thanks!