model: support arch `DbrxForCausalLM` (#6515)
* model: dbrx convert to gguf
#6344
* llama: support dbrx
#6344
* doc: dbrx: add the model as supported
* scripts: get-wikitext-2 add unzip
* llama: increase maximum experts allowed
* llama: factorize moe graph implementation between grok, mixtral and dbrx
---------
Co-authored-by: Megha Agarwal <16129366+megha95@users.noreply.github.com>
