[GHA][BE] Update to newer checkout action (#90969)
This one uses node-16 so it would not spew that many warnings
Also, change `build` to `test` in `_binary_test_linux` to fix https://github.com/pytorch/pytorch/issues/83044
Pull Request resolved: https://github.com/pytorch/pytorch/pull/90969
Approved by: https://github.com/seemethere, https://github.com/ZainRizvi
