Rename Inference Benchmarks to Inference Metrics

[gopal-raj-suresh]

Summary

Updated the section title from 'Inference Benchmarks' to 'Inference Metrics' and modified the related notes for clarity.

Type of Change

• Bug fix
• New feature / enhancement
• Documentation update
• Refactor (no behavior change)
• Chore (dependencies, CI, tooling)

Changes Made

Updated section title and Table of Contents anchor from Inference Benchmarks to Inference Metrics in README.md

How to Test

• Open README.md and confirm the section heading reads "Inference Metrics"
• Confirm the Table of Contents anchor link works correctly

Checklist

• I have read the Contributing Guide
• My branch is up to date with main
• New environment variables (if any) are documented in .env.example and the README
• No secrets, API keys, or credentials are included in this PR
• I have tested my changes locally

Screenshots (if applicable)

N/A