Proposed changes

This PR replaces time.time() with time.perf_counter() in the logistic regression example.

Problem: time.time() is non-monotonic and susceptible to system clock adjustments, which can lead to inaccurate throughput (it/s) measurements.
Solution: time.perf_counter() provides a high-resolution, monotonic clock ideal for benchmarking.

Checklist

• I have read the CONTRIBUTING document
• I have run pre-commit run --all-files to format my code / installed pre-commit prior to committing changes
• I have added tests that prove my fix is effective or that my feature works
• I have updated the necessary documentation (if needed)