Prevent automatic cuda init in init_rpc (#80180)
Fixes #80141
Only initialize cuda if there are devices specified in `init_rpc`
Differential Revision: [D37458309](https://our.internmc.facebook.com/intern/diff/D37458309)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/80180
Approved by: https://github.com/rohan-varma
