Increase test multiprocessing waiting time (#93183)
Fixes https://github.com/pytorch/pytorch/issues/67002
This is a follow-up from https://github.com/pytorch/pytorch/pull/91459 which fixed the flaky test everywhere excepts ROCm and MacOS.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/93183
Approved by: https://github.com/clee2000
