Add CI workflow for running benchmarks

[lola831]

Description

This PR introduces a new GitHub Actions workflow (.github/workflows/run-benchmarks.yml) that runs benchmarks via an issue comment trigger. It verifies that the commenter has sufficient permissions, checks out both the base branch and compare branch (using the merge ref if available), runs benchmarks from tools/benchmarking/ci/benchmarks.py, compares the results with pyperf, and posts the comparison back to the PR comment.

Issue Link

N/A

Checklist

• I have tested the changes locally via pytest and/or other means
• I have added or updated relevant documentation
• I have autoformatted the code with black and isort
• I have added test cases (if applicable)

Additional Notes

N/A

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.66%. Comparing base (b72430c) to head (a53551c).
⚠️ Report is 69 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #341      +/-   ##
==========================================
- Coverage   91.35%   89.66%   -1.69%     
==========================================
  Files          54       48       -6     
  Lines       13584    13194     -390     
==========================================
- Hits        12409    11830     -579     
- Misses       1175     1364     +189     

see 55 files with indirect coverage changes

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• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[dfremont]

Thanks, Lola! I made a couple tiny changes. Will follow up shortly with the actual benchmarks and runner script in a new PR.