NUMA support

[nazar-pc]

Still waiting for user feedback in https://forum.subspace.network/t/numa-support-is-coming/2299?u=nazar-pc, but otherwise this should be ready for review.

The first change here is thread pool manager. Instead of having per-farm thread pools for plotting and replotting, we now have global set of thread pools.

With thread pool manager, we can associate each thread pool with a set of logical CPU cores. Initially this PR tried to pin threads to cores, but performance degraded massively from that. So in later commit I changed that to pin all threads in thread pool to the same set of CPU cores, such that OS kernel is free to move threads between those cores if it sees benefit from doing so.

NUMA support is implemented with hwlocality library that I had to fix in a few places (all upstream already) and cross-compilation still doesn't work on macOS unfortunately (but it is also not immediately beneficial there). Farmer will check which CPU cores belong to which NUMA node and will create number of plotting and replotting thread pools that correspond to number of NUMA nodes present in the system.

NUMA support is introduced using enabled by default numa feature that has additional requirements to installed dependencies, see updated documentation and CI changes.

Lastly, mimalloc crate apparently has NUMA-aware memory allocation support that should further improve plotting performance on NUMA systems, but no one tested yet whether it helps or not, so it is currently behind NUMA_ALLOCATOR environment variable and will either be removed or enabled unconditionally in the future.

Overall this was a somewhat painful process in terms of debugging, but I hope it is worth it.

Along the way I fixed some documentation and CI bugs that affected builds in forks ever since we switched to self-hosted runners.

Code contributor checklist:

• I have read, understood and followed contributing guide

[vedhavyas]

Make sense to me!