rename .pytorch-disabled-tests to disabled-tests.json (#55618)
Summary:
We shouldn't store it as a hidden file, and having the json extension is useful.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/55618
Test Plan: https://github.com/janeyx99/gha-experiments/runs/2298470065?check_suite_focus=true in my own repo
Reviewed By: samestep
Differential Revision: D27651467
Pulled By: janeyx99
fbshipit-source-id: cd9b6c8d065f1ffdcabb0844d375ae8be7177e13
