[TD] Make test class correlation scores available to heuristics. (#111229)
https://github.com/pytorch/test-infra/pull/4617 generates `file_test_class_rating.json`. Now we ensure it's available for heuristics to use during the test step.
(Actual heuristics will come in a separate PR)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/111229
Approved by: https://github.com/huydhn
