separate out flash-attn install (sadly)

examples/seed-oss/README.md

@@ -15,8 +15,8 @@ This guide shows how to fine-tune it with Axolotl with multi-turn conversations
 git clone https://github.com/axolotl-ai-cloud/axolotl.git
 cd axolotl
 
-pip3 install packaging==23.2 setuptools==75.8.0 wheel ninja
-pip3 install --no-build-isolation -e '.[flash-attn]'
+uv sync --extra deepspeed
+uv pip install flash-attn --no-build-isolation
 
 # Install Cut Cross Entropy
 python scripts/cutcrossentropy_install.py | sh