Remove non existent files in multigpu tests (#97393)
They were removed in https://github.com/pytorch/pytorch/pull/96989/files and https://github.com/pytorch/pytorch/pull/96985/files
Pull Request resolved: https://github.com/pytorch/pytorch/pull/97393
Approved by: https://github.com/kit1980, https://github.com/huydhn, https://github.com/fduwjj, https://github.com/malfet
