Fix DataLoader flaky tests that run out of shared memory (#81660)
Fixes #70517 #70547 #74598
I basically disable the `loader_kill` test that would prevent proper clean up, which would be handled by Python interpreter in normal python script execution. However, in pytest framework, the python interpreter never exits and execute clean up on the shared memory using `/multiprocessing/resource_tracker.py`. So, we might encounter the running out of shared memory in some cases.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81660
Approved by: https://github.com/NivekT
