Pin transformer and onnx version for CI

[xiaoyu-work]

Describe your changes

Pin transformer and onnx version for CI

Checklist before requesting a review

• Add unit tests for this change.
• Make sure all tests can pass.
• Update documents if necessary.
• Lint and apply fixes to your code by running lintrunner -a
• Is this a user-facing change? If yes, give a description of this change to be included in the release notes.

(Optional) Issue link

[Copilot]

Pull request overview

This PR aims to stabilize CI by constraining the HuggingFace transformers dependency used by the test pipeline.

Changes:

• Added an upper-bound version constraint for transformers in test requirements.
• Added an inline pylint suppression on a LlamaConfig(...) call in a PyTorch pass test.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
test/requirements-test.txt	Constrains transformers version for CI/test dependency installs.
test/passes/pytorch/test_selective_mixed_precision.py	Adjusts lint behavior for LlamaConfig initialization in a unit test.