feat: cleanup old flex mask patch, suppress Matmul bnb warn, and misc (#3330) [skip-ci]

* feat: add pos id to flex attention for packing part 1

* feat: update to include sliding window mask patch

* fix: suppress MatMul8bitLt: inputs will be cast from warnings

* fix: remove redundant flex attention patch

* chore: update olmo docs

* feat: add validator patch for cross entropy

examples/olmo3/README.md

@@ -16,7 +16,7 @@ This guide shows how to fine-tune it with Axolotl with multi-turn conversations
     axolotl train examples/olmo3/olmo3-7b-qlora.yaml
     ```
 
-Let us know how it goes. Happy finetuning! 🚀
+This uses about 11.3 GiB VRAM. Let us know how it goes. Happy finetuning! 🚀
 
 ### TIPS
 

examples/olmo3/olmo3-7b-qlora.yaml

@@ -42,10 +42,10 @@ wandb_watch:
 wandb_name:
 wandb_log_model:
 
-gradient_accumulation_steps: 4
+gradient_accumulation_steps: 2
 micro_batch_size: 2
 num_epochs: 1
-optimizer: adamw_bnb_8bit
+optimizer: adamw_8bit
 lr_scheduler: cosine
 learning_rate: 0.0002