run_tests.py minor logging changes (#110188)
Minor logging changes that just kind of annoyed me:
* prevent constant printing of `No CUDA runtime is found, using CUDA_HOME='/usr/local/cuda'` by moving import within the function (idk if this is ok)
* prevent constant printing of `Ignoring disabled issues: ['']` (no idea why it was not gated behind a function or main)
* change all prints in run_tests.py to be through stderr so theres no weird interleaving (although if everything goes through stderr, might as well just print everything through stdout...)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110188
Approved by: https://github.com/huydhn, https://github.com/malfet, https://github.com/ZainRizvi
