fix(ci): stabilize BHUSA Python tooling tests

[01rabbit]

Summary

• add an explicit chmod normalization step for bin/azazel-edge-* wrappers before Python tests
• run pytest with PYTHONPATH=.:py so root-level and py/ package imports are both available in CI
• add checkout to the optional dependency-review job so the action has repository contents when enabled

Why

Recent BHUSA closeout tooling added tests that execute local bin/azazel-edge-bhusa-* wrappers. In a fresh GitHub Actions checkout, CI should not depend on implicit executable-bit or import-path assumptions. This PR makes the workflow deterministic for the added tooling tests.

Testing

• Not run locally: repository clone is unavailable from this execution environment.
• Change is limited to GitHub Actions workflow hardening.