Add gpt engineer to ci

[waynehamadi]

Background

Changes

Only run regression tests with mocks, so the tests are faster

PR Quality Checklist

• I have run the following commands against my code to ensure it passes our linters:

  black .
  isort .
  mypy .
  autoflake --remove-all-unused-imports --recursive --ignore-init-module-imports --ignore-pass-after-docstring --in-place agbenchmark