Use kernels from the kernel hub (#2988)
* Use Hub kernels for Marlin and cutlass quantization kernels
* Use hub kernels for MoE/GPTQ-Marlin MoE
* Use attention kernels from the Hub
* Cache the kernels in the Docker image
* Update moe kernels
* Support loading local kernels for development
* Support latest moe kernels
* Update to moe 0.1.1
* CI: download locked kernels for server tests
* Fixup some imports
* CI: activate venv
* Fix unused imports
* Nix: add attention/moe/quantization kernels
* Update hf-kernels to 0.1.5
* Update kernels
* Update tgi-nix flake for hf-kernels
* Fix EOF
* Take `load_kernel` out of a frequently-called function
* Hoist another case of kernel loading out of a somewhat hot function
* marlin-kernels -> quantization
* attention -> paged-attention
* EOF fix
* Update hf-kernels, fixup Docker
* ipex fix
* Remove outdated TODO
