Test PaddleFormers packages custom op trigger

[liuhao2638]

Summary

• Add a minimal file under packages/custom_ops to trigger path-based custom operator detection.
• The changed file path contains a parent directory segment named packages.

Test plan

• pre-commit run --all-files (failed on existing unrelated flake8/trailing-whitespace/copyright/doc spacing issues)
• python -m pre_commit run --files packages/custom_ops/approval_trigger.cu