llama-model: fix unfortunate typo (#18832)

src/llama-model.cpp

@@ -446,7 +446,7 @@ struct llama_model::impl {
     llama_mlocks mlock_bufs;
     llama_mlocks mlock_mmaps;
 
-    // contexts where the model tensors metadata is stored as well ass the corresponding buffers:
+    // contexts where the model tensors metadata is stored as well as the corresponding buffers:
     std::vector<std::pair<ggml_context_ptr, std::vector<ggml_backend_buffer_ptr>>> ctxs_bufs;
 
     buft_list_t cpu_buft_list;