os_linux: Support non-glibc pthread affinity

[jpsamaroo]

musl doesn't have pthread_attr_setaffinity_np, so we need to use pthread_setaffinity_np on thread after pthread_create.

Note: This is not yet tested on master; it was cherry-picked from my 4.5.2 branch, hence why this is a draft PR.

[jpsamaroo]

Also, I don't do #ifdef _GNU_SOURCE because it seems to be defined even on musl.

[dayatsin-amd]

Thanks for the patch. It seems I can use pthread_setaffinity_np so I removed the old calls to pthread_attr_setaffinity_np.

The patch will be part of ROCm 6.1

[dayatsin-amd]

Patch will be included in ROCm-6.1 release