Fix: Propagate flash attn to model loader

[dthuerck]

I noticed that even though setting flash_attn to true in my model config file, llama.cpp kept reporting llama_new_context_with_model: flash_attn = 0. This super-small PR fixes that - turns out the setting wasn't passed on to the model loader.

[abetlen]

@dthuerck thank you!

[BadisG]

I installed the latest version of llama_cpp_python (0.2.70) with this command:

pip install llama-cpp-python \
  --extra-index-url https://abetlen.github.io/llama-cpp-python/whl/cu121

But after using it on oobabooga's software (llama_cpp_hf), I still have this flash_attn = 0 issue:

llama_new_context_with_model: n_ctx      = 2048
llama_new_context_with_model: n_batch    = 2048
llama_new_context_with_model: n_ubatch   = 512
llama_new_context_with_model: flash_attn = 0
llama_new_context_with_model: freq_base  = 8000000.0
llama_new_context_with_model: freq_scale = 1
llama_kv_cache_init:      CUDA0 KV buffer size =  1728.00 MiB
llama_kv_cache_init:      CUDA1 KV buffer size =   832.00 MiB
llama_new_context_with_model: KV self size  = 2560.00 MiB, K (f16): 1280.00 MiB, V (f16): 1280.00 MiB
llama_new_context_with_model:  CUDA_Host  output buffer size =     0.98 MiB
llama_new_context_with_model: pipeline parallelism enabled (n_copies=4)
llama_new_context_with_model:      CUDA0 compute buffer size =   400.01 MiB
llama_new_context_with_model:      CUDA1 compute buffer size =   596.02 MiB
llama_new_context_with_model:  CUDA_Host compute buffer size =    32.02 MiB
llama_new_context_with_model: graph nodes  = 1208
llama_new_context_with_model: graph splits = 3