Add note about flash-attn in README

CHANGELOG.md

@@ -11,6 +11,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Added `DownstreamEvaluatorCallbackConfig` class for running in-loop downstream eval via [OLMo-in-loop-evals](https://github.com/allenai/OLMo-in-loop-evals).
 
+### Removed
+
+- Removed `flash-attn` from the Beaker images since `flash-attn` currently can't be built for torch 2.5.1. We are waiting on updates from the `flash-attn` maintainers. See https://github.com/Dao-AILab/flash-attention/issues/1302.
+
 ## [v1.5.0](https://github.com/allenai/OLMo-core/releases/tag/v1.5.0) - 2024-10-23
 
 ### Added